Styles is the Terps' fourth new addition of the offseason.
The Arlington product is the No. 19 ranked point guard in his class.
The Big Ten hasn't given official word about when the season will start.
Maryland's 2021 recruiting class rises to No. 8 in the nation with Graham's commitment.
Revaz will battle for playing time with Chol Marial and Galin Smith.
Cornish is the No. 77 prospect in the nation per 247Sports.
Smith averaged 1.5 points in 7.6 minutes last season.
Smith averaged 3.1 points and 2.5 rebounds in 31 games last season.
Reese is the brother of incoming women's basketball guard Angel Reese.
Chol Marial and Donta Scott are the Terps' only frontcourt options for next season.