What is Algorand Smart Contract (ASC1)?

Algorand Smart Contracts (ASC1s) are smart contracts that operate on Layer 1 of the Algorand protocol. ASC1s generally represent relatively small smart contracts, with larger smart contracts being reserved for Layer 2. ASC1s are written in an Assembly-like programming language called Transaction Execution Approval Language (TEAL), which is then interpreted by Algorand nodes.