Question - What do you understand by intension and extension?
Answer -
Intension: Intension or most commonly known as Database schema defines the description of the database. This is specified during the database design and mostly remains unchanged.
Extension: Extension is the number of tuples available in the database at any instance of time. This value keeps changing as and when the tuples are created, updated and destroyed. So, the data present in the database at a specific instance of time is known as the extension of the database or most commonly known as the snapshot of the database.