Polkadot JAM has several differences from the typical blockchains in the market.
Polkadot's next biggest update, Polkadot JAM, is not just another smart contract platform or a rollup hub. It’s a new kind of blockchain infrastructure that acts like a flexible, general-purpose blockchain computer. To understand what makes JAM different, it helps to compare it to the main blockchain models you may already know.
Traditional blockchains like Solana, Bitcoin, or the early version of Ethereum are called monolithic blockchains because everything happens in one (mono) layer. Every node in the network has to do the exact same job: process all the transactions, store all the data, and help achieve consensus.
This setup works well when the network is small. But as more people start using it, the system gets overloaded. Every node has more work to do, and that slows everything down.
Polkadot JAM solves this problem by using a sharded model which splits up the work. Instead of having every node do everything, JAM divides tasks among different validator cores which can process things in parallel. This allows the network to process transactions faster and more efficiently.
Blockchains like Ethereum use Layer-2 scaling solutions like rollups to process most of the computation off-chain and only send the finalized data back to the main chain. This helps Ethereum scale without changing its base layer. But different rollups have different rules and levels of compatibility, and this can complicate things.
JAM takes a different approach. It integrates rollup-style processing directly into the chain. Everything follows the same logic, using Refine to process work and Accumulate to save the results. This keeps things unified and easier to trust.
Appchain platforms, like Avalanche, give developers freedom to launch their own blockchains for specific use cases. That sounds great, but it also means you’re responsible for setting up your own validators and security. With JAM, you can get the same level of flexibility without having to set up additional security on your own. You can deploy your own service without needing to manage infrastructure, since JAM services are protected by Polkadot’s shared security and coretime system.
Smart contract chains, such as NEAR, or Aptos, make it easy to build and deploy apps using virtual machines. But because all apps share the same chain, they’re constantly competing for space and compute power. That’s why fees can spike during high usage. JAM solves this by isolating each service into its own space. This way, your app won’t be slowed down by others.. Plus, JAM uses the Polkadot Virtual Machine (PVM), which is faster and more efficient than its counterparts.
What really sets JAM apart is how it brings all of these ideas together. You get the flexibility of smart contracts, the power of appchains, and the scalability of rollups in one system. You don’t need permission to launch something new, and you only pay for the blockspace you use, thanks to agile coretime. In short, JAM gives you more control, better performance, and fewer limitations when you want to build something new on-chain.
