Variables defined inside a function are local to that function and cannot be accessed from outside it. However, a function can access all variables and functions defined in the scope in which it is defined.

In other words, a global function can access all global variables. A function defined inside another function can also access all variables of its parent function, as well as any other variables accessible to the parent function.

In short, a function's scope determines which variables it can access. A local function can only access local variables, while a global function can access all global variables.

// The following variables are defined in the global scope
const num1 = 20;
const num2 = 3;
const name = "Chamakh";
 
// This function is defined in the global scope
function multiply() {
return num1 * num2;
}
 
multiply(); // Returns 60

// A nested function example
function getScore() {
const num1 = 2;
const num2 = 3;
 
function add() {
return ${name} scored ${num1 + num2};
}
 
return add();
}
 
getScore(); // Returns "Chamakh scored 5"