Rhythm is a term used to refer to a "movement characterized by the fixed continuation of strong and dull components, or of conflicting or deviating conditions".
This common definition of regular recurrence or design in time can refer to extensive diversity of cyclical physical appearances having a periodicity or repetition of anything from microseconds to some seconds to some moments or hours etc.
Therefore, repetition and patterns produced by alike or varying form elements in a composition is known as Rhythm.
