REAL is another of the intrinsic data types and x is a REAL variable.
REAL variables are used to store single numbers that can not be represented as INTEGERs. They may have a decimal part or they may be outside of the permitted range for integers. REAL variables can be used to store a wide range of values with varying degrees of precision. They have the disadvantage that, more often than not, there is an element of round-off error (usually, if there are enough significant figures in the representation, only fractions that are whole number powers of 2 will be stored without error).
The details of how REAL variables are stored in memory are normally hidden to the programmer. However, it is important to note that the representation is different to that for INTEGERs and that the associated operators (+, -, *, etc.) represent internal processes that depend on the type of their operands.