Three types of back up :
As the name suggests, Full Copy involves taking back up of all the database this also includes log files, this enables to restore database to the state where the backup was taken
This involves taking the copy of the latest changed data, a Differential backup on top of a full back up allows to restore a database, differential back ups are small, faster and prevent the data loss in case of data corruption, very useful if a part of database is modified more as compared to whole of the database.
Allows to backup the active transaction log when Full or Bulk Logged recovery model is set, so by any means the data is corrupted we can restore it to the last state where the data integrity was upheld. i’ll explain this in another post.