that's what's up

That's excellent; that's great news. A jubilant response to good news or a positive outcome
_________________________________________ اصطلاحی که بیشتر در بین جوانان مخصوصا در امریکا رایجه و اغلب برای بیان شادی یا رضایت از یک پیشامد یا در واکنش به یک خبر یا گفته استفاده میشه.
مثلا در مواقعی که یه نفر حرف سنگینی میزنه یا تیکه سنگین به کسی میندازه هم توسط اطرافیان گفته میشه.
مثل دمت گرم، ایول و. . .
نمونش در فیلم night school
اولی : ?aren't you a little old to be a popstar
دومی : ?aren't you a little young to die
سومی :that's what's up

✳ ( slang )
Used to express acquiescence or concurrence

✳✳ thats wats good.
person says: "yo I just got this/these hot new ( shoes, job, CD, car, etc. )
you say:"THATS WHATS UP!"

✳✳✳ Meaning that you fully understand and/or agree and find yourself excited about the idea or suggestion proposed.
Friend 1: "Yeah so I'm thinking we chill before, and then hit the club by 9. Got mad beer at the crib anyway"
Friend 2: "That's what's up"

✳✳✳✳ To show approval of a person's achievement.
"You got accepted to Harvard? That's what's up, dude. "