The regular way of scoring can be problematic when teams are closely matched and people are waiting to access the court. Since a point can be made only by the serving team, the service can change back and forth forever with no one scoring points.
This is where rally storing is useful. With rally scoring, at the end of every rally, the winning side gets a point, even if they weren’t serving. So, long stalemates are not possible. Every rally ends in someone getting a point.
Everything else about rally scoring is just like regular scoring, sometimes also called “long scoring” or just “long”. In doubles with rally scoring, just like regular scoring, each server on the team gets to serve until a failure, before the serve moves back to the other side.
The typical rally scoring game goes to fifteen points, but any number of points agreed upon is fine.
Like regular scoring, a rally scoring game generally requires winning by two points. So, a stalemate is still possible in which the score goes from let’s say 15-14 to 15-15, to 15-16, to 16-16, etc. The players can decide in advance that winning by one is acceptable to avoid this kind of extra-long game.