drop is done by DA

when DA doesn't think there are enough evidence for conviction.
Or the case doesn't serve any "useful" purpose, or both.
Dismiss is done by Judge when the Judge thinks justice will
not be served by going forward, or DA doesn't have a good enough
case, or both. The end result is the same.
Both of them are used by the system to conserve resources and
put those resources into minimizing crime.


Arrest is done by police, the arrest record will be there
regardless the end result of the case.