The main exhibition held in Castello, in the halls of the Arsenale and Biennale Gardens, alternates between art and architecture (hence the name biennale; biennial). The other events hosted by the Foundation—spanning theatre, music, and dance—are held annually in various parts of Venice, whereas the Venice Film Festival takes place at the Lido.
The Art Biennale (La Biennale d’Arte di Venezia), is one of the largest and most important contemporary visual art exhibitions in the world. So-called because it is held biannually (in odd-numbered years), it is the original biennale on which others in the world have been modeled. The exhibition space spans over 7,000 square meters, and artists from over 75 countries are represented in the collective exhibition spaces as well as in the national pavilions.
The Architecture Biennale (La Biennale d’Architettura di Venezia) is held in even-numbered years. Similarly to the Art Biennale, the exhibition is based on one main exhibition in the arsenale halls, as well as national exhibitions hosted in the pavilions of the arsenale and Biennale gardens.
When the Venice Biennale was founded in 1895, one of its main goals was to establish a new market for contemporary art. Between 1942 and 1968 a sales office assisted artists in finding clients and selling their work, a service for which it charged a 10% commission.
Every other year the Venice Biennale coincides with nearby Art Basel, the world’s prime commercial fair for modern and contemporary art. Numerous galleries with artists on show in Venice usually bring work by the same artists to Basel.
The Venice Biennale has awarded prizes to the artists participating at the Exhibition since the first edition back in 1895. Grand Prizes were established in 1938 and ran until 1968 when they were abolished due to the protest movement. Prizes were taken up again in 1986. The selections are made by the Board of la Biennale di Venezia, following the proposal of the curator of the International Exhibition.
According to Wikipedia