The surroundings or environment. The context given by the surrounding code determines what kind of data a particular expression is expected to return.

A form of scalar context in which an expression is not expected to return any value at all and is evaluated for its side effects alone.

Something extra that happens when you evaluate an expression. Nowadays it can refer to almost anything. For example, evaluating a simple assignment statement typically has the “side effect” of assigning a value to a variable. ...