This Recommendation contains terms and definitions and a framework relevant to providing a general understanding of IPTV. This Recommendation is not simply a compendium of terms and definitions. The primary purpose of this Recommendation is to provide a context for the use of certain terms and definitions to avoid misunderstandings in IPTV and IPTV related activities. Thus@ the definitions are arranged in a specific order and certain necessary relationships are illustrated. This Recommendation uses terms and definitions@ which are considered particularly suitable and applicable to IPTV work and that have already been defined in published ITU-T Recommendations.