This is the 2053rd most frequent Russian word.
всем
"Всем" means "to everyone" or "to all" in English.
Used in the dative case to address a group of people collectively.
Всем привет!
Hello everyone!
Used in the dative case to indicate to whom something is related or concerning.
Он известен всем.
He is known to everyone.
Used in the dative case to signify the recipient of the action of helping.