Callbacks and Higher-Order Functions

A function that takes at least one function as an argument or returns a function
A higher-order function is a function that takes at least one function as an argument or returns a function as its result. This is a key concept in functional programming. Common examples in JavaScript include map(), filter(), reduce(), and setTimeout(). Higher-order functions enable powerful abstractions and code reuse by allowing function composition and delegation.
A function with high priority in the execution context
A function that uses the 'this' keyword
A function that can only be called once