Understanding JavaScript Closures

Closures are one of the most powerful and fundamental concepts in JavaScript, yet they frequently confuse developers.

A closure is the combination of a function bundled together with references to its surrounding state (the lexical environment).

In simple words: a closure gives an inner function access to an outer function's scope even after the outer function has finished executing.

Use cases include data privacy, factory functions, event handlers, and memoization in performant web applications.