Sprint Goal is the single (overarching) objective for the Sprint, achieved through the Increment.
Sprint Goal communicates why the Sprint is valuable to stakeholders, creates coherence and focus.
Collaboratively defined by the Scrum Team during Sprint Planning.
Although the Sprint Goal is a commitment by the Developers, it provides flexibility in terms of the exact work needed to achieve it.
The progress toward the Sprint Goal is inspected on daily basis during the Daily Scrum.
If the Sprint Goal becomes obsolete, the Sprint could be cancelled.