PHP was developed by Rasmus Lerdorf and developed as Open Source and it is a open source technology.
To describe a php page we have to put file extension .php, or if you use any software like dreamweaver or notepad plus, they will auto create an extension of .php. PHP is powerful scripting language for develop a dynamic websites.
A PHP script starts with <?php and ends with ?>:
EXAMPLE 1 :
echo “Hello World”;
Output : Hello World
Note : echo is used for print the value.
EXAMPLE 2 :
Output : 30
Note : echo is used for print the value. $ sign is variable in php language, $ (variable) is used for transfer the value from one place to another place.