How does Rust memory allocation work under the hood?

Rust uses stack allocation by default and heap allocation via allocators like the global allocator for dynamic data structures.

Rust does not have a runtime garbage collector. Stack allocation is used for fixed-size values, while heap allocation is triggered via structures like Box, Vec, and String. The allocator (often jemalloc or system allocator) manages heap memory. Rust's ownership system ensures deterministic deallocation via Drop trait. Unlike GC languages, memory is freed immediately when ownership goes out of scope.