Snapshots capture the state of a system at a specific point in time, providing a quick way to revert a system back to that state. They are particularly useful in scenarios when you need to restore a system to the most recent state without the time-consuming process of a full restoration. On the other hand, 'Alternate location' refers to restoring data to a different location than the original, 'In place' refers to restoring data in the original location where it was lost, and 'Restore files' means to restore specific files instead of the complete system or data set.