The Scrum process model sets the framework in which all product development actions occur. Product development is divided up into clearly defined intervals, usually 2 to 4 week long sprints. At the end of each Sprint a team must be deliver software ready to be delivered and usable by itself even if the production were to be stopped. The course of a Sprint that consists of totally different roles, meetings and artefacts is called Scrum Flow. The central theme of each meeting is the idea of continual improvement.
Click: Boris Gloger explains Scrum Flow in this video