Exactement, c'est ça, je suis d'accord en totalité

Absolument !

It means that they agree with you. We can say "tout à fait" or "c'est ça" or "exactement", "bien sûr" etc.... to say that we agree. It depends on the topic and the person who you are talking to.

It means like absolutely or of course. For example if you asked "can you excuse me for a second i need to take a call" someone would respond with a tout a fait meaning yes of course go ahead its like used in more formal situations where someone asking more out of politeness instead of actually wanting a yes or no response