Scope, Closures & the Execution Context

Two main scopes:

• Global scope – accessible everywhere.
• Function scope – created by each function.
• Block scope – created by let/const.

A closure is a function that remembers the environment in which it was created.

Example: Simple closure

function makeCounter(){
  let count = 0;
  return function(){
    count += 1;
    return count;
  };
}
const counter = makeCounter();
console.log(counter()); // 1
console.log(counter()); // 2