# How can you intuitively explain the term 'phase'? [closed]

'Phase' refers to the term encountered while studying waves (in phase, out of phase etc).

When you have a periodic process, phase means how far along it you are. Typically one full cycle corresponds to a phase difference of $2\pi$, because the simplest example of periodicity is moving along a circle, and $2\pi$ is the angle in radians of a full revolution. This is also why you will sometimes see phase measured in degrees.
A closely related meaning is when you have two copies of a periodic process. In this case, the phase difference (sometimes abbreviated to just phase) measures just that, how much farther along one of the waves (or whatever) is. Two things that are in phase are oscillating together; two things that are $180°$ out of phase are at exactly opposite points in their cycles.