PHP: Operators – Manual

Operator are mainly divided by three groups that are totally seventeen types. = “equal to. + = Union. == = Equality. === = Identity. != = Inequality. <> = Inequality. !== = Non-identity. “ = backticks . @ = at sign. ++$a = PreIncrement. $a++ = PostIncrement. –$a = PreDecrement. $a– = Postdecrement. && = And. || = Or. ! = Not. and = And.

https://www.php.net/manual/en/language.operators.php