Glossary
Developer cache
Files a developer tool keeps so the next build or install can skip a download or a compile.
Compilers and package managers cache aggressively. The npm cache, Gradle's dependency cache, Cargo's downloaded crates, and Xcode's DerivedData are all developer caches. They are recreatable at the cost of time and bandwidth. They are also why a laptop that builds software fills up while the documents folder looks modest.
Disk Housekeeper Smart Clean targets this set, plus node_modules. Removal is previewed and goes to the Trash by default. The practical page is Clean npm, Gradle, and Cargo caches.