Stack vs Heap

Analogy: the stack is like a stack of books.

Stack

• Simpler and faster, but more limited.
• Holds method frames, local variables, value types.
• Memory is reclaimed automatically when a frame exits.

Heap

• Slower and a bit more complex, but allows more sophisticated structures.
• Objects can outlive the call stack (reference types).
• Static variables also live here.

Notes

• Async methods may run on different threads — relevant to heap-allocated state lifetimes.
• This is language/runtime-dependent (the note is framed around .NET/JS-style value vs reference).

Open questions

• Garbage collection & stack vs heap in our runtime (Node/V8).
• Stack overflow causes; object lifetime & closures.