they are important because animals inthe savanna need them to survive
They're in Africa because the climate in Africa supports the wildlife that lives there.
It is a hot, seasonally dry grassland with scattered trees. It is intermediate between a grassland and a forest.
Great Plains and California, US. Serengetti, Congo, Angola, Africa. South and Central America and the caribbean. Australia and New Guinea. The greatest area of savannas is Africa.
The term was originally used for tropical grasslands. It is a little broader now, but in essence it still means grasslands.