Solana primarily uses Rust and C for smart contract development. Rust is a system programming language that offers memory safety and concurrent programming features. It's known for its performance and safety, particularly in maintaining thread safety. C, on the other hand, is an older, low-level language known for its efficiency. Understanding these languages is crucial for a Solana developer as the Solana software development kit (SDK) supports them. Additionally, for building DApp frontends and interacting with the Solana blockchain, knowledge of JavaScript and familiarity with Web3.js or Solana's JavaScript API is necessary.