Difference between Scrum and Extreme Programming

Scrum	Extreme Programming
Scrum's main goal is to get estimations of how long development will take.	XP is more about helping developers get things done as quickly and maintainable as possible.
Team typically works in iterations (called sprints) that are from two weeks to one month long.	Team typically works in iterations that are one or two weeks long.
Scrum teams do not allow changes into their sprints.	XP teams are much more agreeable to change within their iterations.
Product owner prioritizes the product backlog but the team determines the sequence in which they will develop the backlog items	Work in a strict priority order which is set by Product Owner
Scrum provides agile management mechanisms and doesn’t prescribe any engineering practices	XP prescribes engineering practices like test-driven development, the focus on automated testing, pair programming, simple design, refactoring, and so on.
SCRUM places great responsibility in the Scrum Master, who manages the development team.	In XP, the practice of collective ownership allows any programmer to modify a section of code when it needs to be fixed.
XP requires that the software be validated at all times, to the extent that tests are written prior to the actual software.	In SCRUM, validation of the software is completed at the end of each Sprint during the Sprint Review, not at each step within the Sprint.