# Runtime ℹī¸ The runtime (in other words, a state transition function), refers to the core logic of the blockchain that is responsible for validating blocks and executing the state changes they define. 💁 The runtime in this template is constructed using ready-made FRAME pallets that ship with [Polkadot SDK](https://github.com/paritytech/polkadot-sdk), and a [template for a custom pallet](../pallets/README.md). 👉 Learn more about FRAME [here](https://paritytech.github.io/polkadot-sdk/master/polkadot_sdk_docs/polkadot_sdk/frame_runtime/index.html).