Приве́т, как дела́?
pree-vyét, kak dee-lá
Hi, how are you?
Передава́й ему́ приве́т от меня́.
pye-rye-da-váî ye-mú pree-vyét at mee-nyá
Give him my regards. (Say hello to him from me.)
"Привет" means "hi" in Russian. It's an informal greeting and used between friends, family and people of young age.
In formal situations, with people you don't know, or with the ones that are older than you, you should use "здравствуйте".