Integers: are whole numbers, without a decimal point, like 4195.
Doubles: are floating-point numbers, like 3.14159 or 49.1.
Booleans: have only two possible values either true or false.
NULL: is a special type that only has one value: NULL.
Strings: are sequences of characters, like 'PHP supports string operations.'
Arrays: are named and indexed collections of other values.
Objects: are instances of programmer-defined classes, which can package up both other kinds of values and functions that are specific to the class.
Resources: are special variables that hold references to resources external to PHP (such as database connections).