What is Where?
Where is (adv) 1. (asking a question) in what place, to what place Where did I put my glasses? Do you know where the restaurant is? Where are the knives and forks? Where are you going for your holiday? 2. in a place in which Stay where you are and don’t move. They still live in the same house where they were living twenty years ago. Here’s where the wire has been cut. 3. whenever Use fresh tomatoes where possible. (NOTE: After where used to ask a question, the (verb) is put before the subject: Where is the bottle? but He doesn’t know where the bottle is.)
source: Easier English, Student Dictionary Upper Intermediate Level