What is the difference between passer rating and QBR?

Passer rating is a 1973 formula on four box-score rates — completion percentage, yards per attempt, touchdown rate and interception rate — capped at 158.3 and blind to everything else. QBR is ESPN’s model, built from play-by-play: it charges sacks and fumbles to the quarterback, credits his runs, adjusts for the defence he faced and weights plays by how much they changed the chance of winning. A quarterback who throws for 300 empty yards after the game is decided rates well on the first and poorly on the second.

Passer Rating (RTG) in fullQBR (QBR) in full