The call stack is primarily used for function invocation (call).
Since the call stack is single, function(s) execution, is done, one at a time, from top to bottom. It means the call stack is synchronous.
LIFO: 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.

A stack overflow occurs when there is a recursive function (a function that calls itself) without an exit point. The browser (hosting environment) has a maximum stack call that it can accomodate before throwing a stack error.