Cosmos is known as a decentralized network of independent parallel blockchains, each supported by BFT (Byzantine Fault Tolerant) consensus algorithms like Tendermint. In other words, Cosmos is a blockchain ecosystem that can scale and interoperate with each other. Before Cosmos, blockchains operated in silos, unable to communicate with each other, and creating and processing blocks on them required significant effort. Cosmos addresses these blockchain issues with a new technical vision. Understanding this vision brought by Cosmos requires delving into the basics of blockchain technology.

The developers of Tendermint, the gateway to the Cosmos ecosystem, are Jae Kwon, Zarko Milosevic, and Ethan Buchman. Although Kwon still appears as the chief architect, he stepped down from the CEO position in 2020. Peng Zhong took over as CEO of Tendermint, making significant changes among the management team. Their goals are described as improving the experience offered to developers, creating an enthusiastic community to use Cosmos, and creating educational resources on the subject.

To understand what a blockchain is, it is necessary to know that there are blockchain validators, which can be well-intentioned or malicious. Even if some of the validators (less than a third) are malicious, a blockchain can be defined as a digital ledger recorded by a correct set of validators. Each party keeps a copy of the ledger on their computer and updates it according to the rules defined by the protocol when they receive transaction blocks. The goal of blockchain technology is to ensure the ledger is copied correctly, meaning every honest party can instantly see the same version of the ledger. The main contribution of blockchain technology is that it allows parties to share a digital ledger without the need to act under a central authority. The first and most famous application of blockchain technology is Bitcoin, a decentralized currency. From a more technical perspective in the blockchain network, the blockchain is known as a state machine replicated across all nodes (nodes), maintaining consensus security as long as no more than a third of the blockchain providers are present.

Architecturally, blockchains can be divided into three conceptual layers:

The state machine is the same as the application layer. It defines the state of the application and the state transition functions. Other layers are responsible for replicating the state machine across all nodes connected to the network.

The Story of Bitcoin (Blockchain 1.0)
To understand how Cosmos fits into the blockchain ecosystem, it's essential to historically understand the concept of blockchain. The first blockchain was created in 2008, a peer-to-peer digital currency called Bitcoin, which used a new consensus mechanism known as Proof of Work. The first decentralized application on the blockchain is Bitcoin. Shortly after, individuals, realizing the potential of decentralized applications, began producing new ones in this world of applications with the desire to build them. In the early days of the Bitcoin blockchain era, there were two options for developing decentralized applications: forking the Bitcoin codebase or creating a new system on this codebase. However, the Bitcoin codebase had a very monolithic structure (all three layers; networking, consensus, and application, were integrated). Additionally, there was a need for better tools due to the limited and user-unfriendly programming language of Bitcoin.
The Story of Ethereum (Blockchain 2.0)
In 2014, Ethereum entered the ecosystem with a new project to create decentralized applications. Ethereum achieved this by transforming the application layer into a virtual machine called the Ethereum Virtual Machine (EVM). This virtual machine allows any developer to deploy programs called smart contracts to the Ethereum blockchain without permission. This new approach allowed thousands of developers to start creating Decentralized Applications (DApps). However, the limitations of this approach soon became apparent and continue to this day.

Scalability
The first limitation is known as scaling. Decentralized applications built on Ethereum are blocked at a shared rate of 15 transactions per second. This is because Ethereum currently uses Proof of Work and Ethereum's decentralized applications compete for the limited resources of a single blockchain.
Usability
The second limitation is the limited flexibility given to developers. The EVM (Ethereum Virtual Machine) is a virtual space that must maintain all usage transactions, thus optimizing for the average usage transaction. This means that developers must compromise the design and efficiency of their applications (e.g., requiring the use of an account model in a payment platform where the UTXO model might be preferred). They are limited to a few programming languages and cannot apply automatic code generation, among other factors.
Independence
The third limitation is that all applications share the same fundamental environment, limiting each application's independence. This limitation creates two management layers: the application layer and the underlying layer. If an error occurs in the application, nothing can be done without the approval of Ethereum's management. If the application requires a new feature in the EVM (Ethereum Virtual Machine), the approval of Ethereum's management is again necessary to accept this feature.
These limitations are not unique to Ethereum; all blockchains trying to create a single platform suitable for all use cases encounter these types of limitations. The difference with Cosmos is precisely at this point.

The vision of Cosmos is to facilitate the creation and interconnection of blockchains by allowing developers to transact with each other. The main goal here is to create an internet of blockchains that can communicate with each other in a decentralized manner. Cosmos allows blockchains to maintain their autonomy, process transactions quickly, and communicate with other blockchains in the ecosystem. This vision is achieved with a series of open-source tools designed to allow people to quickly create private, secure, scalable, and interoperable blockchain applications, such as Tendermint, Cosmos SDK, and IBC. In addition to the technical architecture of the Cosmos network, some of the most important tools in the ecosystem include Cosmos, initially created as an open-source community project by the Tendermint team. Moreover, any user has the authority to create additional tools on this platform to elevate the developer ecosystem to a higher level.

Until recently, creating a blockchain required building the three layers (Networking, Consensus, and Application) from scratch. Ethereum simplified the development of decentralized applications by providing a virtual machine blockchain where any user could deploy their special logic in the form of smart contracts. However, it did not simplify blockchain development. Go-Ethereum, very similar to Bitcoin, remains a monolithic technology stack that is difficult to fork and customize. Tendermint came into play at this point, created by Jae Kwon in 2014. Tendermint BFT (Byzantine Fault Tolerance) is a solution that packages a blockchain's networking and consensus layers in a general engine, allowing developers to focus on application development rather than the complex underlying protocol. As a result, Tendermint saves hundreds of hours of development time. Tendermint BFT (Byzantine Fault Tolerance) has also named the Complex Fault Tolerant (BFT) consensus algorithm used in the Tendermint BFT engine.
The Tendermint BFT (Byzantine Fault Tolerance) engine connects to the application through a socket protocol called the Application Blockchain Interface (ABCI). This protocol can be implemented in any programming language, thus allowing developers to choose a language that suits their needs. However, these features are not limited to this information. The features that make Tendermint BFT (Byzantine Fault Tolerance) a new blockchain engine technology are described as follows.

While Tendermint BFT offers the possibility to reduce the development time of a blockchain, creating a secure ABCI (Application Blockchain Interface) application from scratch is difficult. The existence of the Cosmos SDK is based on this difficulty. Cosmos SDK is a generalized framework that simplifies the process of building secure blockchain applications on top of Tendermint BFT. It is based on two main principles:
Modularity: The aim of the Cosmos SDK is to create an ecosystem of modules that allows developers to easily spin up application-specific blockchains without having to code each functionality of their applications from scratch. Any user can create a module for the Cosmos SDK, and using ready-made modules in the blockchain, transferring them to the application is as simple as that. For example, the Tendermint team has created a set of core modules necessary for the Cosmos Hub. These modules can be used by any developer when building their applications. Additionally, developers can create new modules to customize their applications. As the Cosmos network grows, the ecosystem of SDK modules will expand, making it increasingly easy to develop complex blockchain applications.
Capability-based Security: Capabilities limit the security boundaries between modules, allowing developers to reason better about the composability of modules and limit the scope of malicious or unexpected interactions.
The Cosmos SDK also comes with a set of useful developer tools for creating command-line interfaces (CLI), REST servers, and other commonly used utility libraries. Additionally, like all Cosmos tools, the Cosmos SDK is designed to be modular. Today, it allows developers to build on top of Tendermint BFT. However, it can also be used with any other consensus engine that implements ABCI. Over time, multiple SDKs built with different architectural models and compatible with multiple consensus engines are expected to emerge. The area where all these are provided is the Cosmos Network.

One of the most significant features of the Cosmos SDK is its modularity, allowing developers to port almost any existing blockchain codebase written in Golang onto the Cosmos SDK. For example, Ethermint is a project that ports the Ethereum virtual machine into an SDK module. Ethermint operates exactly like Ethereum but also benefits from all the features of Tendermint BFT. All existing Ethereum tools (Truffle, Metamask, etc.) are compatible with Ethermint, allowing smart contracts to be transferred without additional work.

This question becomes important considering that most decentralized applications today are developed on virtual machine blockchains like Ethereum. First, it should be noted that until now, blockchain development has been much more challenging than smart contracts. With the Cosmos SDK, the situation has changed and updated positively. Project developers have various advantages of developing application-specific blockchains easily. Among others, they offer more flexibility, security, performance, and independence. A person who does not want to create their blockchain can make their smart contracts compatible with Cosmos by deploying them to Ethermint.

Now that there is a way for developers to quickly create customized blockchains, it can be explained how blockchains will be connected to each other. The connection between blockchains is facilitated through a protocol called Inter-Blockchain Communication (IBC). IBC allows heterogeneous chains to transfer value (i.e., tokens) or data to each other by taking advantage of the instant finality feature of Tendermint consensus (although it can work with any "fast finality" blockchain engine).

Heterogeneous chains are divided into two:
Different layers: Heterogeneous chains have different layers, meaning they can differ in how they implement the networking, consensus, and application sections. To be compatible with IBC, a blockchain only needs to follow a few requirements; the most important is that the consensus layer must have fast finality. Proof of Work chains (like Bitcoin and Ethereum) do not fall into this category because they have probabilistic finality.
Independence: Each blockchain is protected by a set of validators responsible for agreeing on the next block to be committed to the blockchain. In Proof of Work blockchains, these validators are called miners. An independent blockchain is a blockchain that has its validator set. In most cases, since the validators are responsible for changing the state, it's important for blockchains to be independent. In Ethereum, all applications are run by a common validator set. Hence, each application has only a limited amount of independence. IBC allows heterogeneous blockchains to transfer tokens and data to each other; this means blockchains with different applications and validator sets can interoperate. For example, it allows general and private blockchains to transfer tokens to each other. Currently, no other blockchain framework provides this level of interoperability.

The idea behind the IBC system is quite simple. Consider an example where an account on chain A wants to send 10 tokens (ATOM) to chain B:
Tracking
Continuously, chain B receives headers from chain A and vice versa. This ensures that each chain monitors the validator set of the other. Essentially, each chain is running the client of the other.
Locking
When an IBC transfer is initiated, the ATOM is locked (bonded) on chain A.
Proof Relay
Then, a proof that 10 ATOMs are bonded is transferred from chain A to chain B.
Verification
The proof is verified on chain B according to the header of chain A, and if deemed valid, 10 ATOM vouchers are created on chain B.
Note that since ATOM exists only on chain A, the ATOM created on chain B is not real ATOM. They are a representation of ATOM on chain A on B and proof that the ATOMs on chain A are frozen.
A similar mechanism is used to unlock the ATOM when it returns to the origin chains.

IBC is a protocol that allows two heterogeneous blockchains to transfer tokens to each other.
One of the proposed ideas is to directly connect each blockchain in the network to each other through IBC connections. The main problem with this approach is that the number of connections in the network grows quadratically with the number of blockchains. If there are 100 blockchains in the network and each needs to maintain an IBC connection with each other, this would mean 4950 connections. This rate can spiral out of control. To solve this, Cosmos proposes a modular architecture with two classes of blockchains: Hubs and Zones.
Zones are what are normally considered heterogeneous blockchains, while Hubs are blockchains specially designed to connect Zones to each other. When a Zone and a Hub establish an IBC connection, it automatically gains access to all other Zones connected to it (i.e., it can send and receive). As a result, each Zone only needs to establish a limited number of connections with a limited number of Hubs. Hubs also prevent double spending between Zones. When a Zone receives a token from a Hub, it only needs to trust the Hub and the token's origin Zone. The first Hub launched in the Cosmos Network is known as the Cosmos Hub. The Cosmos Hub is a public Proof of Stake blockchain with its native staking token named ATOM, and transaction fees can be paid in multiple tokens.

The structure of Cosmos shows how Tendermint-based chains can interoperate. However, Cosmos is not limited to Tendermint chains. In fact, any type of blockchain can connect to Cosmos. At this stage, two situations need to be distinguished: chains with fast finality and chains with probabilistic finality.

Blockchains using any fast finality consensus algorithm can connect to Cosmos by adapting IBC to work with them. For example, if Ethereum had transitioned to Casper FFG (Friendly Finality Gadget), it could have adapted IBC to work with Casper, creating a direct connection between it and the Cosmos Ecosystem.

For blockchains without fast finality, such as Proof of Work chains, the process is a bit more complex. For these chains, a special type of proxy chain called a Peg-Zone is used. A Peg-Zone is a blockchain that tracks the state of another blockchain. The Peg-Zone itself has fast finality and is therefore compatible with IBC. The role of the Peg-Zone is to provide finality for the chain it bridges. For example:
Example: Ethereum Peg-Zone
To enable token transfers between Ethereum and Cosmos, it's desired to bridge the Proof of Work Ethereum blockchain. Since Proof of Work Ethereum does not have fast finality, a Peg-Zone acting as a bridge between the two is required. First, the Peg-Zone must decide on a finality threshold for the starting chain. In other words, it can consider a block on the starting chain as final once 100 blocks have been added after it. Secondly, a contract is deployed on the main Ethereum blockchain, and users who want to send tokens from Ethereum to Cosmos start by sending their tokens to this contract. The contract then freezes the assets and after 100 blocks, issues a representation of these assets in the Peg-Zone on Cosmos. A similar mechanism is used to unlock the assets when they are sent back to the Ethereum chain.
The Peg-Zone also allows users to send any token existing in Cosmos to the Ethereum chain (Cosmos tokens are represented as ERC-20 tokens on the Ethereum chain). The Tendermint team is working on an implementation of an Ethereum chain Peg-Zone called Peggy. Peg-Zones need to be customized for the specific chain they bridge. Creating an Ethereum Peg-Zone is straightforward because Ethereum is account-based and has smart contracts. However, creating a Bitcoin Peg-Zone can be more challenging than creating an Ethereum Peg-Zone.

Now that it has been explained how blockchains can be easily created, another issue to address is scalability. Cosmos benefits from two types of scalability:
Vertical scalability: Methods for scaling the blockchain itself. Moving away from Proof of Work and optimizing its components, Tendermint BFT can reach thousands of transactions per second. For example, an application like a virtual machine (e.g., the Ethereum virtual machine) imposes a much lower limit on transaction throughput than an application with directly embedded transaction types and state transition functions (e.g., a standard Cosmos SDK application). This is one reason why application-specific blockchains make sense.
Horizontal scalability: Even if the consensus engine and application are highly optimized, a single chain's transaction volume will inevitably hit a barrier at some point. This is the limit of vertical scaling. To go beyond this, the solution is to move to multi-chain architectures. In other words, having multiple parallel chains running the same application and operated by a common set of validators, making blockchains theoretically infinitely scalable.
The good vertical scalability offered by Cosmos will be a significant improvement over existing blockchain solutions on its own. Later, it will implement horizontal scalability solutions after the completion of the IBC module.

Cosmos, thanks to the modularity of Tendermint BFT and Cosmos SDK, makes blockchains powerful and easy to develop. Cosmos allows blockchains to transfer value to each other through IBC and Peg-Zones while maintaining their autonomy.
Cosmos enables the scaling of blockchain applications to millions of users through horizontal and vertical scalability solutions. Above all, Cosmos is not a product but an ecosystem built on a set of modular, adaptable, and interchangeable tools. Developers are encouraged to join the effort to improve existing tools and create new ones to realize the promise of blockchain technology. These tools are the foundation needed to build tomorrow's decentralized internet and global financial system.

ATOM coin has a unique total supply amount of 260,906,513. These cryptocurrencies are earned through staking rather than mining.
There were two private sales for ATOM in January 2017, followed by a public sale in April of the same year. After these two sales, a price of approximately $0.10 per ATOM coin was established, and the total market value reached $16 million. The distribution of the total token amount is as follows: 80% to investors and the remaining 20% to two companies, All In Bits and Interchain Foundation.
The ATOM tokens of the Cosmos network are likened to ASIC hardware used for Bitcoin mining.

It is mentioned in this article that Cosmos uses the Proof of Stake consensus algorithm. Validator nodes with a high amount of ATOM tokens have a higher chance of being selected to validate transactions and earn rewards. Nodes that do not act according to the rules risk losing their tokens as punishment.

For those wanting to invest in cryptocurrencies, the question of how to buy and sell Cosmos (ATOM) is frequently asked. This can be done either by mining or using a cryptocurrency exchange created specifically for these transactions.
In Turkey, buying Cosmos (ATOM) with Turkish Lira is surprisingly easy and fast. You can buy Cosmos (ATOM) without needing any technical knowledge or official documents.