There are two kinds of releases, dead and dynamic. Both are good releases, although you will find advocates who push one or the other as being best. Among the prominent archers you will hear about on this forum, Rick Welch is one of the main proponents of the dead release, while Rod Jenkins is one of the main proponents of the dynamic release.
Both releases involve pulling until the shot is released. If you stop pulling, you start collapsing, which could be a problem if you feel that you are opening your fingers. There should be no conscious opening of your fingers. Admitedly, this is a precise use of language, because it is fine if there is a relaxing of the fingers and letting the string push them aside, or a subconscious release that just happens, but not fine if you just open them.
The difference between a dynamic release and a dead release is whether you are pulling through the shot, as opposed to just pulling until the shot goes off. If you are pulling through the shot (dynamic release), your string hand should end up somewhere in the vicinity of your neck, or shoulder next to your neck. If you are pulling and just waiting for the shot to go off (dead release), your string hand doesn't move much after the shot.
If you want an example of a dynamic release, you can look at Masters of the Bare Bow 3, Rod Jenkins section.