The story usually makes it quite clear who belongs in which group, as they tend to work separately, so the series rarely refers to the differences.

A series in baseball terminology refers to two or more consecutive games played between the same two teams.

Further series refer to regularly flash jumping between the galaxies.

A 900 series refers to three consecutive perfect games bowled by an individual bowler.

Each series of vehicle registration refers to a year and hence its age.

A limited series refers to a comic book series with a clear beginning, middle and end.

The temporal series refers to objects and events in time (as opposed to space).

The series generally refers to members of species simply as "cats".

Harmonic series may refer to either of two related concepts:

The series repeatedly refers to Rucker as the defending champion.