Functions

• Programs are assigning the values to the memory or variables and running the program to do somethings with the variables.

• without functions programs can't do anything.

Function Expression:

var canada = function() {
    console.log("cold");
}

Function Declaration:

function india() {
    console.log("warm");
}

Function Invocation/Call/Execution:

canada(); // defined at run time that what this function does
india();  // defined at parse time - hoisting

• Function invocation will create an Execution context that gives an this (=window) and arguments object.