What's the difference between these two sentences ? Are they same?
1. This is a book which is famous in Japan now.2. This is the book which is famous in Japan now.

Question

Answer

There is a difference. The second sentence refers to a book that had already been a topic of conversation. Eg. This is THE book I was telling you about. The first sentence implies the listener is hearing about it for the first time.

Answer

The first one sounds better