Scrum is the name of one of the agile methodologies. It is simple and lightweight. Scrum framework receives complex problems of software development and divides them into batches. 

The software development process in Scrum is delivered in sprints, no longer than 3 weeks in length. Typical Scrum roles are a Product owner (to make clear the idea of the product to a team of developers), a Scrum Master (a connection between a project owner and a development team) and Development team (software engineers, QA engineers, developers, UX/UI designers). 

See also Kanban, Scrumban.