Variable is name of memory location used to store some data.
In PHP no need to provide data types at the time of variable declaration because PHP is loosely types language .
Variable names start with ‘$’ symbol.
Local variable :-
Variable declaration within the function comes under local variable .
Local variable of a function cannot be accessed from another function.
Global variable :-
Variable declaration outside of all function come under global variable.
Global variable can be accessed from any function within the script.
Note:- We can not access global variables directry from function by using ‘$’ GLOBALS keyword. We can access global variable by using ‘$ GLOBALS’ key from functions.
Variable variables :-
If we assign a variable name as the value of another variable comes under variable variables ,
Static variables :-
Static variable can remember previous value . we can assign value only one time into static variable.
Reference variable :-
It is an alias name of a variable . both refers the value of same address locations.
Super Global variable :
PHP support no of super global variable . these variable we can access from any web page in application. All super global variables are array data types available