Pop music
In the more specific sense of this word, pop music means a music style and a type of the modern mass culture. It means not only popular music but also music that is based on the traditional pop rhythms of the western world. In different regions of the world it is based on western pop rhythms, although separate elements of the local types of traditional music may be also present. Besides, pop music is able to imitate and absorb elements of musical styles that are the most popular at a particular moment of time, but the general rhythmic basis is always the same. That's why pop music has little influence on other genres and styles of music.
Another characteristic feature of pop music is its commercial basis. This is probably the most notable phenomenon: no pop song was ever created without the initial intent to earn money. That's why many people may call various other styles of music "pop" if they are primarily created, performed, advertised and popularized with the obvious intent to make as much money as possible. Unfortunately, a lot of other music genres, having become trendy and popular, although they were originally opposed to pop music as the most fake and insincere art, are now used by music producers in the same way.
Every year hundreds of festival and contests are organized in order to both reveal the greatest pop performers and, again, advertise pop music to a wide audience (for example Grammy Awards, Eurovision, MTV Awards and many others). To measure the popularity of pop musicians various charts are yearly or monthly presented to TV viewers and radio listeners.