Why are interfaces preferred to abstract classes?

Question

I recently attended an interview and they asked me the question \"Why Interfaces are preferred over Abstract classes?\"

I tried giving a few answers like:

Answer 1

As devinb and others mention, it sounds like the interviewer shows their ignorance in not accepting your valid answers.

However, the mention of JDBC might be a hint. In that case, perhaps they are asking for the benefits of a client coding against an interface instead of a class.

So instead of perfectly valid answers such as "you only get one use of inheritance", which are relating to class design, they may be looking for an answer more like "decouples a client from a specific implementation".