Understand and use functions in PHP

To this question they are many answers all pointing out the same concept and idea. Here are some: > Functions are "self contained" modules of code that accomplish a specific task. Functions usually "take in" data, process it, and "return" a result. Once a function is written, it can be used over and over and over again. Functions can be "called" from the inside of other functions. Source: http://www.cs.utah.edu/~germain/PPS/Topics/functions.html > A function is a piece of code which takes one more input in the form of parameter and does some processing and returns a value. Source: http://www.tutorialspoint.com/php/php_functions.html But practically what does that mean if your are beginner or you have never been in touch with functions? To help you undertsand that let me take a real example of a **bird**. You know creating softwares/applications is similar to creating these beings. So imagine you have to create that bird, you will start by making it bones, flesh and parts, feathers, etc. upon that you will have the possibility for it to *sing*, *walk*, *fly*, *jump*, etc. This actions are the bird's functions(*walk*, *jump*, *fly*, *sing*).