What is the difference between sprint and iteration

Summarizing one of the StackOverflow threads:

- Iteration is a common term in iterative and incremental development (IID).

- Scrum is one specialized flavor of IID.

- Sprint is a scrum specific name for the iteration.

All sprints are iterations but not all iterations are sprints…

As to the sprint length: anything goes as long as the sprint is timeboxed i.e. it is finished on the planned date and not “when it’s ready”. It does help to have the sprints of similar durations.