The combination of select, insert, update and delete operations is called DML (Data Manipulation Language). If you are dealing with databases, it is definitely something you should know.
Some of those:
SELECT
It is used to take records from the database.
INSERT
We use it to insert records into the table.
UPDATE
We use it to update the records in the table.
DELETE
It is used to delete records in the table.
You can follow my other articles for detailed explanations of the above concepts.