Exactly... / Precisely... / That's right...
Strong affirmation agreeing with what was just said. More emphatic than sí or claro. Very common in conversation to show you fully agree.
—So the problem is communication. —Exactly.
Precisely, that's what I wanted to say.
—They were late because of traffic? —That's right.
—So the problem was the price? —Exactly, that's it.
Exactly, there's no need to explain further.