Music from popular films, TV series and cartoons.
When a blockbuster film is released, or during and after a television series airs, an album in the form of a soundtrack is typically released alongside that.
A soundtrack typically contains instrumentation or alternatively a film score. But it can also feature songs that were sung or performed by characters in a scene (or a cover version of a song in the media, rerecorded by a popular artist), songs that were used as intentional or unintentional background music in important scenes, songs that were heard in the closing credits, or songs for no apparent reason related to the media other than for promotion, that were included in a soundtrack.
Soundtracks are usually released on major record labels (just as if they were released by a musical artist), and the songs and the soundtrack itself can also be on music charts, and win musical awards.
By convention, a soundtrack record can contain all kinds of music including music “inspired by” but not actually appearing in the movie; the score contains only music by the original film’s composers.
Contemporaneously, a soundtrack can go against normality, (most typically used in popular culture franchises)
and contains recently released and/or exclusive never before released original pop music selections, (some of which become high charting records on their own, which due to being released on another franchises title, peaked because of that) and is simply used for promotional purposes for well known artists, or new or unknown artists. These soundtracks contain music not at all heard in the film/television series, and any artistic or lyrical connection is purely coincidental.
However depending on the genre of the media the soundtrack of popular songs would have a set pattern; a lighthearted romance might feature easy listening love songs, whilst a more dark thriller would compose of hard rock or urban music.