PHP has a total of eight data types that we use to construct our variables: 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).