DeutschWhen researching Polkadot, you will encounter terms like interoperability, Parachain, or sharding. Below, we explain what the cryptocurrency DOT is, how the network works, and what has changed since the switch to Polkadot 2.0.
What is Polkadot?
Polkadot was launched by Ethereum co-founder Gavin Wood, who also wrote the protocol for it. The goal is to solve the problem of interoperability. It is therefore about the secure and trustworthy exchange between different blockchains.
In short, Polkadot is a blockchain network to which developers can connect their own blockchain. The central blockchain forms the core and is called the Relay Chain. Connected blockchains are referred to as Parachains. The coin of the Polkadot cryptocurrency is called DOT.
What was Polkadot developed for?
In addition to scalability, a lack of interoperability is one of the biggest problems of blockchain-based solutions. This means that different blockchains cannot be linked and interact with each other. The individual blockchains thus form isolated solutions.
Polkadot addresses three key areas. First, interoperability, meaning communication between blockchains. Second, scalability, by distributing tasks across multiple Parachains via sharding. Third, security: Parachains share the security of the Relay Chain instead of having to build their own validator network. This principle is called Shared Security.
How does Polkadot work?
Central to this system is the Relay Chain, to which the Parachains are connected. It handles consensus and coordination for the entire network.
Relay Chain and Parachains
Parachains benefit from the ability to communicate with other Parachains via the Polkadot network. Additionally, they share the secure network provided by the Relay Chain. Each Parachain is a specialized blockchain with its own rules, for example, for DeFi, gaming, or NFTs. Consensus finding and state communication are clearly separated within the network. This distinguishes Polkadot from Bitcoin and Ethereum, where this separation does not exist.
Blockchains connected to the Relay Chain share the same consensus mechanism. A single Parachain therefore does not need to recruit its own validators to secure itself. It inherits the security of the Relay Chain. For small projects, this significantly lowers the barrier to entry, as there is no need to build a separate secure validator set.
From Slot Auctions to Agile Coretime
The way Parachains gain access to the network has fundamentally changed. Understanding both the old and new models helps to grasp why Polkadot functions differently today than it did at its launch.
The former model: Slot Auctions
Previously, there was only a limited number of Parachain slots. These slots were allocated through an auction process for a fixed term. Anyone who wanted to win a slot had to lock up large amounts of DOT for the duration of the contract. This model tied up capital for years and was primarily sustainable for established projects.
The current model: Agile Coretime
With Polkadot 2.0, this model was replaced. Instead of long-term slot leases, teams now purchase computation time on the Relay Chain, known as Coretime, in smaller or larger blocks. According to the official Polkadot documentation, Agile Coretime is the scheduling system through which Parachains flexibly access cores. There are two variants: Bulk Coretime for longer reservations in advance, and On-demand Coretime, which is paid per block in DOT. Meanwhile, all Parachains have transitioned to this Coretime market.
Elastic Scaling, Async Backing, and JAM
Other components of Polkadot 2.0 are built upon Coretime. Async Backing accelerates block production. Elastic Scaling allows a chain to rent multiple cores simultaneously when needed, thereby dynamically increasing its computing power. The longer-term roadmap is called JAM (Join-Accumulate Machine). JAM is a redesign of the consensus layer, enabling Polkadot to execute smart contracts directly at the core level, rather than just relaying messages between blockchains. JAM is currently in the testnet and specification phase and is not yet active on the mainnet.
Interoperability in Polkadot
Polkadot separates two types of communication: within its own ecosystem and externally to foreign networks.
Within the ecosystem, Parachains exchange messages via Cross-Consensus-Messaging (XCM). Since they share the same consensus, they do not need external intermediaries for this.
For external connections, Polkadot requires so-called Bridges. These are a special form of Parachains and create bridges to other crypto networks such as Bitcoin or Ethereum. This allows a unit of Bitcoin, in tokenized form, to be used, for example, in the Ethereum DeFi sector. Bridges are technically complex and are considered a cross-network attack vector, which is why their security remains a separate issue.
Consensus and Security: Nominated Proof of Stake
Polkadot uses the Nominated Proof of Stake (NPoS) consensus mechanism. In this system, multiple actors collectively secure the network.
Validators stake DOT and verify both the Relay Chain and the Parachains. Together with other validators, they check transactions, reject invalid ones, and add new blocks to the Relay Chain. Collators collect transactions from their Parachain and prepare blocks from them for the validators. Nominators do not perform an active technical role. However, DOT holders select good validators and thus support security. For this, they receive a reward in the form of DOT.
DOT Tokenomics: What is DOT used for?
DOT fulfills several functions within the network. You need the coin for staking and thus for network security, for governance (i.e., voting on network decisions), and for paying for resources like Coretime and transaction fees.
Regarding the money supply, much changed in 2026. Polkadot introduced a hard cap of 2.1 billion DOT, ending the previous model of unlimited emission. The annual new issuance was reduced by more than 50 percent. Additionally, 80 percent of the revenue from Coretime sales, as well as a portion of the fees, are burned and thus permanently removed from circulation. This shifts DOT from an inflationary to a scarcer supply.
Polkadot Staking for Beginners
With staking coins, it is generally possible to stake your coins and receive a reward for it. In Polkadot, this is done by nominating validators.
As a nominator, you select one or more validators and stake DOT for them. If the validator operates reliably, you receive proportional rewards. However, there are risks. If a validator behaves incorrectly or attempts to defraud, a portion of the staked DOT can be withheld through so-called slashing. Even a validator with frequent outages will reduce your earnings. The actual reward depends on the total amount of DOT staked, the number of active validators, and network parameters, and is not guaranteed.
Advantages and Disadvantages of Polkadot
Polkadot offers solutions to problems that even large blockchains struggle with. At the same time, its design brings its own weaknesses.
In favor of Polkadot is Shared Security, which allows even small Parachains to secure themselves without building their own validator network. With Agile Coretime, the allocation of blockspace has become flexible and predictable. The multichain design allows for specialized blockchains that operate in parallel.
Against Polkadot is its high technical complexity, which makes entry difficult for developers and users. Its success heavily depends on the activity of the individual Parachains. And the bridges to external networks remain a security-critical point.
Polkadot in Comparison: Ethereum, Cosmos, and Solana
Polkadot is best understood by comparing it to other well-known networks.
Compared to Ethereum, Polkadot is not a single Layer-1 blockchain, but a layer that connects many blockchains and provides them with shared security. Ethereum, on the other hand, scales primarily through separate Layer-2 networks. Like Polkadot, Cosmos pursues a multichain approach, but each chain there is responsible for its own security. Polkadot bundles security via the Relay Chain. Solana, in turn, is a single blockchain designed for high throughput without a Parachain structure. Cardano also relies on a single chain at its core. Polkadot distinguishes itself from all others through its combination of shared security and many specialized Parachains.
Buying and Safely Storing Polkadot
Polkadot is one of the more well-known cryptocurrencies by market capitalization and is tradable on numerous exchanges and with brokers. It is important to choose a regulated and trustworthy provider before you want to buy Polkadot or trade DOT. You can find a structured overview in the crypto exchange comparison.
After purchase, you can leave DOT in the exchange account. For larger amounts, this is not recommended. For longer-term storage, a crypto wallet, ideally a hardware wallet, is suitable. Only when you are in possession of your so-called private keys do you have full control over your coins.
Conclusion
Polkadot connects many specialized Parachains via the Relay Chain and provides them with shared security. With the transition to Agile Coretime, the network has replaced the old auction model and made access more flexible. Through Async Backing, Elastic Scaling, and the JAM roadmap, the project is working on higher throughput. For the DOT coin, the hard cap of 2.1 billion units introduced in 2026 ended the previous inflation model. How Polkadot holds its own against networks like Ethereum, Cosmos, and Solana depends on how many applications and users the Parachains attract.
