When you introduce a clause that describes a noun you previously mentioned in a sentence then you are talking about Relative Pronouns. So relative pronouns connect sentences or phrases. So we have four sets of relative pronouns in Spanish:
que
quien
el que
el/la/los/las que
el/la/los/las cual.
Some uses are the following:
Answer:
translated to "what breaks without being touched?"
answer to the riddle; a promise, or even silence
