In the Scrum Framework all activities needed for the implementation of entries from the Scrum Product Backlog are performed within Sprints (also called 'Iterations'). Sprints are always short: normally about 2-4 weeks.
Each Sprint follows a defined process as shown below:
The Sprint Process
Each Sprint start with two planning sessions to define the content of the Sprint: the WHAT-Meeting and the HOW-Meeting. The combination of these two meeting are also defined as Sprint Planning Meeting. In the WHAT-Meeting the Scrum Team commits to the User Stories from the Scrum Product Backlog and it uses a HOW-Meeting to break the committed User Stories into smaller and concrete tasks. Then implementation begins.
At the end of the Sprint a Sprint Review Meeting is conducted to allow the Scrum Product Owner to check if all of the committed items are complete and implemented correctly. Additionally a Sprint Retrospective Meeting is conducted to check and improve the project execution processes: What was good during the Sprint, what should continue as it is and what should be improved.
During the Sprint a short daily Standup-Meeting (Daily Scrum Meeting) is held to update the status of the items and to help self-organization of the team.