The NBA's free agency negotiation period officially kicked off at 6 p.m. ET on Friday, ahead of the league's annual moratorium period, which began Saturday at midnight. Deals can be agreed to during this period but can't be officially signed until Thursday.

While this year's list of free agents doesn't contain as many superstars as those in years past, there could be plenty of player movement via trades, which we've seen in recent offseasons.

Among the big names who were free agents was Toronto Raptors point guard Fred VanVleet, who agreed to a three-year, $130 million deal with the Houston Rockets. Point guard Kyrie Irving re-signed with the Dallas Mavericks on a three-year, $126 million deal.

A player is an unrestricted free agent (UFA) when he is not under contract and is free to sign with any NBA team without any obligation to his former team. A restricted free agent (RFA) is still under control by his current team, but he is not on the roster and is free to seek offers from other teams.

However, before an RFA can accept an offer from another team, his current team must have the opportunity to at least match that offer to retain him. If his current team matches that offer, then that player must remain with his current team.