A Sprint is a time-box of one month or less after which a “Done”, useable, and potentially releasable product/service increment is created (official definition in the Scrum Guide).
A Release may contain one or more Sprints with a start and end date. In the Sprint Planning, the Product Owner and the team will add Stories spanning the time period in effort days.
The team can define Tasks for each Story to further detail implementation chunks.
During the Sprint period, the team will mark the Tasks as done, while they finish each Task. The Story can only be set to done, when all its tasks are done.
The team uses the Sprint Backlog to change the state of Stories/Tasks and to follow the progress.