The major difference between C-band and Ku-band satellite transmission involves the allocation of the frequencies. C-band is assigned to terrestrial microwave radio communications while Ku-band is allocated solely to satellite communication networks.
Because of its broader allocation, C-band frequencies can overlap with other communications. It is, however, considered more robust because it is not as affected by rain and for that reason is the frequency of choice in Africa in regions prone to torrential rain.
C-band frequencies are preferable where there are requirements for large bandwidth. Ku-band uses smaller antennas and less expensive equipment and so is the choice of smaller networks, broadcasting and two-way internet connections.