The official definition from ETSI is "A selection of services marketed as a single entity".
As an example, in the UK some broadcast channels are transmitted in regional variants - the programmes are mostly the same but the adverts are different and there is some local content. The Sky DVB-S platform broadcast all of these variants, so the receiver needs to have a way to select which version of the channels to make available. Sky have created regional Bouquets which are broadcast alongside the EPG, the user enters the location when setting up the receiver and it uses the bouquet to select which version of the regional channels to make available.
