Vocal music is a type of music performed by one or more singers, either with instrumental accompaniment, or without instrumental accompaniment (a cappella), in which singing provides the main focus of the piece. Music which employs singing but does not feature it prominently is generally considered instrumental music as is music without singing. Music without any non-vocal instrumental accompaniment is referred to as a cappella.
Vocal music typically features sung words called lyrics, although there are notable examples of vocal music that are performed using non-linguistic syllables, sounds, or noises, sometimes as musical onomatopoeia. A short piece of vocal music with lyrics is broadly termed a song.
Vocal music is probably the oldest form of music, since it does not require any instrument besides the human voice. All musical cultures have some form of vocal music.
Usually, light vocal refers to cinematic music, such as bollywood, tollywood etc. Film music is termed as light vocal, as there is much less use of meends and aalaps in any given song, than it's counterpart. Though all songs in film music are raga based, the use of intricate swings are much less in use.