Citation:
Definition: The ! (NOT) operator is a unary operator that negates the value of a boolean expression. It returns true if the expression is false, and false if the expression is true.
The && (AND) operator combines two boolean expressions and returns true only if both expressions are true.
The || (OR) operator combines two boolean expressions and returns true if at least one of the expressions is true.
Boolean expression: A boolean expression is an expression that evaluates to either true or false.