What is the importance of the transaction log tail in transaction log backups?

What will be an ideal response?

The tail is the active transaction log that contains the database changes since the last transaction log backup. The active transaction log could become corrupted or deleted. If this should occur, the ability to complete a point-in-time restore for the time frame of events recorded in the transaction log or to restore the database to the current state is lost. As the tail grows in size, the level of this exposure increases.