A backlog is a list of tasks or work items that need to be completed. It can refer to a prioritized list of functionality that a product should contain in agile project management, or a list of tasks required to support a larger strategic plan. A backlog can also refer to an accumulation of tasks unperformed or materials not processed.

In agile project management, a product backlog is a prioritized list of functionality that a product should contain. It is considered an artifact within the scrum software development framework and is created and continuously maintained by the product owner. A sprint backlog consists of selected elements from the product backlog that are planned to be developed within a particular sprint.

A backlog is important because it serves as a master repository of every valid request, idea, and possibility for the product, product extensions, or even entirely new offerings. It facilitates conversations among a cross-functional team and helps the team discuss how to prioritize work on a product. A well-maintained backlog allows technical teams to begin thinking about how they might implement items and mitigate any conflicts, dependencies, or advanced work required.

In summary, a backlog is a list of tasks or work items that need to be completed. It can refer to a prioritized list of functionality that a product should contain in agile project management or a list of tasks required to support a larger strategic plan. A backlog is important because it serves as a master repository of every valid request, idea, and possibility for the product, facilitates conversations among a cross-functional team, and helps the team prioritize work on a product.