Glossary
Language server
The background process that gives a code editor autocomplete, go-to-definition, and error checking for a language.
Editors such as VS Code, Cursor, and Windsurf do not understand each language themselves. They run a language server for it, such as tsserver for TypeScript, pyright for Python, or rust-analyzer for Rust, and ask it questions as you type. Each open project can have its own, inside the editor's extension host.
Language servers can grow large over a long session. Stopping one is safe in the sense that the editor starts a fresh one automatically, with a short pause in autocomplete. Sentinely offers that restart when a language server is holding a lot of memory. See When VS Code or Cursor slows your Mac.