The phrase "what's the difference between" is commonly used to ask about the distinction or contrast between two or more things. It is a standard English expression often translated into other languages such as German as "Worin unterscheiden sich ...?" or "Was ist der Unterschied zwischen ...?"

. Separately, "What's the Difference" is also the title of a hip hop song by Dr. Dre featuring Eminem and Xzibit from Dre's 1999 album 2001. The song explores differences between the artists and other rappers, with lyrical themes including personal reflections and storytelling

. In summary:

• As a phrase, "what's the difference between" is a question used to inquire about distinctions.
• As a proper noun, "What's the Difference" refers to a specific song by Dr. Dre featuring Eminem and Xzibit.

These are distinct uses: one is a general English phrase for comparison, the other is a musical work title.