In the comics, Cloak is the poor street-smart individual and Dagger is from a privileged, well-educated family. The series swaps these character backgrounds -- Cloak is now a prep school student and Dagger is a street-smart thief.
The character of Detective O'Reilly was mentioned in the Luke Cage, Season 2 episode If It Ain't Rough, It Ain't Right (2018) as having recently moved to New Orleans. This is the first example of cross-platform Marvel Cinematic Universe TV shows having an established connection.
Cloak & Dagger was originally intended for Netflix with the same hard edge tone as the other series. After Marvel announced all future properties would be reserved for Disney affiliated stations, the series was toned down for airing on Freeform.
This is the first live-action television appearance of Cloak and Dagger. The pair previously appeared in animated TV shows Ultimate Spider-Man and Wolverine vs. Sabretooth.
Ty and Tandy are never referred to as "Cloak" or "Dagger" during the entire series run, nor in the Runaways crossover.