It explains it in clear terms:
"""
Zed's language support is built on two main technologies:
Tree-sitter: This handles syntax highlighting and structure-based features like the outline panel.
Language Server Protocol (LSP): This provides semantic features such as code completion and diagnostics.
These components work together to provide Zed's language capabilities.
"""
Note this is _not_ how VSC's C++ Intellisense works. The VSC C++ plugin uses proprietary features of MSVC, it doesn't use LSP.
