Bedu is another word for a Bedouin: a person from the traditionally desert-living Arab peoples, especially of Arabia and nearby lands, historically moving with animals rather than farming in one village. In English you will see Bedouin far more often in news and school books; Bedu is a shorter form used in some writing and by some speakers. Treat them as the same people, not two different groups. The word is usually a name for a people (often with a capital B), not a casual adjective for ‘anyone from a desert.’