What is the call stack?

A call stack is a mechanism for an interpreter (like the JavaScript interpreter in a web browser) to keep track of its place in a script that calls multiple functions — what function is currently being run and what functions are called from within that function, etc.

At the most basic level, a call stack is a data structure that uses the Last In, First Out (LIFO) principle to temporarily store and manage function invocation (call).

LIFO: When we say that the call stack, operates by the data structure principle of Last In, First Out, it means that the last function that gets pushed into the stack is the first to be pop out, when the function returns.

In summary The key takeaways from the call stack are:

1. It is single-threaded. Meaning it can only do one thing at a time.
2. Code execution is synchronous.
3. A function invocation creates a stack frame that occupies a temporary memory.
4. It works as a LIFO — Last In, First Out data structure.