Release backlog is used to release features. Sprint backlog is used for each sprint. Release backlogs contain all product features (backlog), release date (priority) & release order, while sprint backlogs only contain the release plan decided during release planning.

release backlog vs sprint backlog

Release Backlog: In release plan, release backlog contains all requirements/features of a release over a certain period of time , organized in the priority order with respect to business value or benefit from market feedback.

Sprint Backlog: It is a smaller set of items that must be completed within a specified time frame – one week or two week – also known as iteration . During the Sprint planning meeting, it’s decided what will go into this iteration , during the release planning meeting what  is planned for release in the upcoming release.

Sprint backlog contains all stories that are part of release backlog with added details such as  story point , story estimate, tasks and subtasks, along with the dependency between them.

Both release and sprint backlogs contain a list of functionality requirements to be considered for a product release or a one-week/ two week iteration respectively .

Release backlog is simply a list of items which need to go into release plans. If you’re using Scrum methodology then these stories will become the Sprint Backlogs which you will break down into tasks during Sprint Planning Meeting (SPM). In short: Release backlog answers “What” needs to be done in release. Sprint Backlog answers “How” it will be done in release.

Single release planning:  The release plan is created once for a release and ideally comprises high-level requirements . It specifies release wide features and does not substantially detail the work required to achieve them, nor does it include timeframes or any other estimates.

Multiple release planning:  Release plans are adjusted throughout a release as priorities change and scope becomes better understood. The release backlog is broken down into smaller portions such as sprint backlogs so that each can be planned and resourced separately.

Sprint backlog consists of user stories which need to go through one week/two weeks iterations (depending on what you agree with your team) to produce product increment ready for release in various product development methodologies.  Sprint backlog also consists of release milestones, these release milestones are defined in release plan, therefore they are the release scope outputs to be delivered by sprints/iterations.

Release backlog is a multiple release backlog. It should not consist of user stories which need to go through iterations because it would have needed to plan and estimate that at first place before breaking it down into release milestones which will be planned and estimated during release planning.

Differences between Release backlog and sprint backlog are:

1. Release backlog is multiple release backlog, whereas sprint backlog is for a release.
2. Release backlog consist of release milestones, release planning and release estimation  agreed in release planning session while sprint backlog consists of all detailed user stories agreed in release planning and detailed release plan.
3. Release items can contain technical tasks such as creating test cases or creating artifacts required to complete the item at a later stage depending on different types of process followed by organization. Such tasks might not always be part of sprint backlog because it might need to go through iteration/sprint before they are ready for consumption such as existing documents that need updating or preparation of documentation related to product delivery which can take time during implementation.
4. Release items have dependency with other release items based on release plan.
5. release items should have a release date before planning release backlog.
6. Release items can be planned for release during next or future release cycles even if it has not reached the minimum level of readiness to go into sprints in current release cycle which is also known as rolling wave planning technique.
7. Release item is part of sprint backlog when there are tasks related to specific sprint against a release item and ready to start development in current or following sprint, meaning it has reached minimum level of readiness in current/following release cycle to enter sprint.

8 . Release items are managed in release backlog not sprint backlog.

9. Release items must be used when release date is fixed and release backlog does not contain any specific release, meaning no release date is set for release.
10. Release item contains tasks related to the release development process like stabilization & performance testing which can be done in multiple sprints before releasing the product.
11. Rolling wave planning technique helps to plan releases beginning with high level features then work down into detailed functionalities while continuous flow of developing user stories keeps project dynamic.

Thus Release backlog and sprint backlog are the backlogs which are different from release items & sprint items. release backlog & release items are used for release planning while sprint backlog & sprint items are used for release or sprint planning. But both are important at the same time, release items can be used to release early if the product is ready for release using release planning.

Sprint backlog & sprint items are used for sprint planning which is done in daily standup so both release backlog & release items are not necessary here rather than sprint backlog & sprint items are necessary in daily standup.