Boolean values can only have values of true or false.

Boolean Expressions

Sometimes a programmer would like a statement, or group of statements to execute only if certain conditions are true.
There may be a different statement, or group of statements that are to be executed when the condition is false.
An expression that can be evaluated to true or false is called a Boolean expression. (Named after a mathematician named Boole.)

Examples of Boolean Expressions:  (X and Y are variables)

x == 5	(True if x has a value equal to 5)
x > y	(True if x is greater than y; example x is 7, Y is 3)
x < y	(True if x is less than y; example X is 2, y is 2.5)
x != y	(True if x is not equal to y; example x is 5, y is 6)
x >= y	(x is greater than or equal to y; example x is 4, y is 3 or 4)
x <= y	(x is less than or equal to y; example x is 4, y is 4 or 5)

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