In Microsoft SQL Server, checkpoint is a very important process which helps to write all modifications made in the database from buffer cache to disk.
This process helps to reduce the possibility of data loss in case of any disaster or system failure.
Lazy Writer is also available in SQL Server to write modified data from buffer cache to disk if everything is normal.
But this approach may not work properly in case of system failure or unexpected shutdown.
To overcome this situation, SQL server has Checkpoint feature which transfers all modified pages to disk.
