Insert: Used to add new records to the database. You can insert records for standard and custom objects.
Update: Used to modify existing records in the database. You can update one or more fields of existing records.
Delete: Used to remove records from the database. You can delete one or more records at a time.
Upsert: Used to either insert a new record or update an existing record based on a specified external ID field. If a record with the given external ID already exists, it's updated; otherwise, a new record is inserted.
Merge: Used to combine up to three duplicate records into a single master record. Only available for some standard objects.
Undelete: Used to recover a previously deleted record within a certain retention period (usually 15 days).
