Classical physics is a set of physics theories that predate present day, greater complete, or greater broadly relevant theories. If a presently established principle is taken into consideration to be present day, and its advent represented a main paradigm shift, then the preceding theories, or new theories primarily based totally at the older paradigm, will frequently be known as belonging to the location of "classical physics".

Modern physics is a department of physics both advanced withinside the early twentieth century and onward or branches substantially inspired via way of means of early twentieth century physics. Notable branches of present day physics encompass quantum mechanics, unique relativity and popular relativity.