This varies by university, you will need to ask any relevant member of staff at your university (or, at the very least, fellow students at your universitiy so it would be useful if you posted in the relevant subforum or, if it doesn't have one, specify the university). Even if you do obrain information from students it isn't necessarily accurate.
But, as a general rule, you do usually need to pass all credits in order to gain an honours degree (allowances can be made if failed modules are first year modules but not if second, third or fourth year modules). If you fail modules (the exact credit vallue will vary) you will receive an ordinary degree - a degree without honours. Again, it does vary, so you will need to ask or consult an relevant documentation which might be found on the university website.