These words are alike in denoting a group of things which come or are brought together in some particular order or according to a plan. The words are further alike in that the order they refer to is one in which the things grouped together follow one another. Sequence designates a following in space, time or thought, and suggests that the things brought together are done so according to some logical system: making sure the chassis parts were added in proper sequence ; the sequence of arguments in discourse. Succession emphasizes the following, on after the other, of similar objects or events, without interruption. Unlike sequence , succession can, but does not necessarily, imply a logical ordering: a succession of hereditary kings; a succession of catastrophes.

Progression fixes the attention chiefly upon the act, process or state of moving forwards and has particular reference to mathematics and music. A mathematical progression is a sequence of numbers or quantities, each of which is derived from the preceding by a constant relationship. Musical progression can designate either a succession of tones, chords, etc., or the movement from one tone or chord to another.

A series is a number of things ordered or arranged according to a similarity of nature or on the basis of like relationships. Although it is therefore very much like sequence or succession, series suggests the individuality of the connected things rather than the mere fact that they follow one another: along series of successes in the theatre.