Task in Project Management
A task is a concrete task in the development process. It represents the smallest necessary unit that is implemented to achieve the goal of a sprint. A user story comprises one or more tasks.
A task is more technical compared to the functional requirements in the product backlog which can represent a functional or non-functional requirement for the product. A task that goes beyond two person days should normally be broken down into smaller tasks, because otherwise the granularity of the estimated values no longer fits the purpose of the sprint backlog.