This is the Africa Cup of Nations, which because of sponsorship is sometimes called the Orange Africa Cup of Nations. The 2012 tournament was the 28th and was held in Equatorial Guinea and Gabon. The Africa Cup is organised by the Confederation of African Football (CAF). It has been going since 1957 and is held every two years.

When the first tournament was held there were only three countries in it: Ethiopia, Sudan and Egypt. South Africa was excluded due to its apartheid policies, an early example of the international actions that would eventually help to end the apartheid regime. Now 16 nations compete, with Egypt being the most successful overall.
Previously the Africa Cup of Nations has been held in even-numbered years. In 2013, however, an extra tournament will be held and from then on the two-yearly event will be held in odd-numbered years, so as not to clash with the World Cup.
You can find out more about this tournament here.