What is exchange control?

Excuse me, could you elaborate on the concept of exchange control? As someone who is relatively new to the field of finance, I'm curious to understand what it entails. Is it a regulatory measure put in place by governments to control the Flow of foreign currencies within and outside their borders? And if so, what are the primary objectives behind implementing such a system? Additionally, how does it affect the overall stability of the financial system and the economy as a whole?