This is the 754th most frequent Spanish word.
dónde
"Where."
In this question, 'dónde' asks the location of the addressed person at the current moment.
¿Dónde estás ahora?
Where are you now?
Here, 'dónde' introduces the location inquired about in an indirect question.
Quiero saber dónde compraste ese libro.
I want to know where you bought that book.
In this sentence, 'donde' introduces a relative clause, signifying the location related to the initial statement.