# Smart Contracts A smart contract is a type of computer program that runs automatically on a blockchain network when certain predefined conditions are met. These smart contracts are used to automate transactions and business processes, eliminating the need for middlemen and increasing transaction security and efficiency. Smart Contracts are written in specific programming languages such as **Solidity**, Rust (and more!) and run on a blockchain network, which means that all parties involved in the transaction can verify the code and conditions of the contract. This transparency helps ensure that transactions are fair and that there is no room for fraud. There are several blockchain networks that support smart contracts, including: **Ethereum** Is the most popular blockchain network for smart contracts. It supports the Solidity programming language and has a large community of smart contract developers. **Polygon, Celo, Avalanche C Chain, BNB Chain and Stratus** Based on the architecture of Ethereum, these networks are called EVM (Ethereum Virtual Machines) and also use Solidity in their Smart Contracts. They have the same implementation structure and usability, and allow bridges between protocols. There are differences in performance, transaction costs and adoption. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.cryptum.io/english/community-edition/sdk-guides/smart-contracts.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.