retreat or withdraw?

Hello, Mou Mou—and welcome to English Forums.

Most synonyms mean the same outside of any context. Your two words also do. Please supply a sentence or two using them which confuse you.

for example
he talked To us for an hour and then withdraw.
here can the word 'withdraw' be replaced with retreat? Is the word retreat mostly used in military? thanks!

Retreat is usually used in a military sense, or in a way equivalent to the military sense, to move back from a position or to back away from a threat.
Withdraw, in the military sense, may be used to mean retreat, or it may be used to indicate leaving after an attack (the paratroopers attacked the airfield, destroying twenty planes, before withdrawing with only li

Both are a bit formal for your sentence, however, Mou Mou, so neither sounds quite right. A native speaker would more likely say this:

He talked to us for an hour and then left.

thank you for your help!now i get it.

The words technically mean the same thing, but I tend to find, the manner in which they are used is different, to put it in context, if used as a military term, a retreat is when your army is suffering badly and you're all running from the battle to try and regroup elsewhere, to withdraw means to leave the battle, but the army is more organized and in control, they aren't fleeing for their lives,

The Italians objected to the proceedings and withdrew from the conference. (They left deliberately, calmly under protest.)

After the knock-down-drag-out argument, her son retreated to his room and immersed himself in virtual reality games.

Retreat - to escape to a safe, comfortable place after a fight.