In JavaScript, a function is a reusable block of code that performs a task. You define it once and can call it whenever you need it. 1. Basic function function greet () { console . log ( " Hello! " ); } greet (); Here, greet is the function name, and greet() calls the function. 2. Function with parameters Parameters let you pass information into a function: function greet ( name ) { console . log ( " Hello, " + n...