There are a variety of contracts in the NBA, ranging from guaranteed to ten-day contracts.
If a player is on an Exhibit 10 contract with a particular team, it would allow him to participate in that franchise's training camp. The team will control that player's G League rights, and he is eligible to get $50,000 if he manages to spend 60+ days with the G-League affiliate. Signing a basketball athlete to an Exhibit 10 contract works out well for NBA teams, who hold the option to cut them or include them in the roster if they play well.
Amier Ali's cousin, Yusuf Ali, was recently hired as an assistant coach at ASU. Well, this strategy worked back in the day with Sendek and a highly regarded recruit named James Harden who came along with his high school coach, Scott Pera. The offer list that this kid is really impressive - Kentucky, Alabama, Kansas, and Arkansas were the others in his top five.