what does the push function do in js code example

Example 1: javascript array push

var SomeRandomArray = [];
SomeRandomArray.push("Hello, world!");

Example 2: javascript array push

let animals = ["dog","cat","tiger"];

animals.pop(); // ["dog","cat"]

animals.push("elephant"); // ["dog","cat","elephant"]

Example 3: javascript push

const animals = ['pigs', 'goats', 'sheep'];

const count = animals.push('cows');
console.log(count);
// expected output: 4
console.log(animals);
// expected output: Array ["pigs", "goats", "sheep", "cows"]

animals.push('chickens', 'cats', 'dogs');
console.log(animals);
// expected output: Array ["pigs", "goats", "sheep", "cows", "chickens", "cats", "dogs"]