In the philosophy of time, presentism is the belief that neither the future nor the past exists.
The opposite of presentism is ‘eternalism’, which is a belief in things that are past and things that are yet to come exist eternally.
One other view (that has not been held by very many philosophers) is sometimes called the growing block theory of time, which is a theory that takes the past and present to exist but the future to be nonexistent.
Presentism is compatible with Galilean relativity, in which time is independent of space but is probably incompatible with Lorentzian/Einsteinian relativity.
Presentism can also be used more loosely to refer to a narrow focus on the conditions of the moment.