Question: In Scrum methodology, is it possible to have multiple iterations before a product is considered shippable for a release?
I think Release and Iteration should have a one-to-one mapping so that at end of every iteration a product is ready for a release, but not sure.
Traditionally scrum calls for a "potentially releasable product" at the end of each sprint. )From the "Sprint" definition found here: https://www.scrum.org/Resources/Scrum-Glossary)
Of course, there may be business or other reasons to delay that release. Such as a launch date tied to new regulations/laws that go into effect in the future.
There are ways around this kind of thing though such as the use of feature flags so that the software is fully tested and released, but the feature is not yet enabled. This has its own overhead and not a slam dunk approach for every team.
Other teams have gotten to a point beyond 1:1::iteration:release. They actually release every feature immediately upon completion. Their "definition of done" includes releasing to production. This is summarized in a recent tweet by Jeff Sutherland (co-creator of Scrum) "Get your stories small, use one code branch, and everything goes to production " https://twitter.com/jeffsutherland/status/503569798924472320
There is no one right answer for every team, but releasing more frequently is almost always a good thing.