Que 1:- what is PHP?

PHP is server side Scripting language which is embedded with HTML. PHP is generally used to develop dynamically web based application. The full form of PHP at that time was Personal Home Page. But now it is known as Hypertext Preprocessor. PHP is an Open Source.

Que 2:-which compiler is used in PHP?

Phalanger compiler is used in PHP.

Que 3:- how we declare variable in php?

Variable is a storage area which is used to store data. In php we declare variable using dollar ($).

Que 4:- is it necessary to assign a value to variable before use it?

Yes. It is necessary to assign vale to variable before use it otherwise it will show error.

Que 5:-what is the advantage of php?

It is an open source.

It is easy to learn.

Fast and Light weight