A sequence is a user-defined schema bound object that generates a sequence of numeric values according to the specification with which the sequence was created.
The sequence of numeric values is generated in an ascending or descending order at a defined interval and can be configured to restart (cycle) when exhausted.
Sequences, unlike identity columns, are not associated with specific tables.
Create Sequence
Get Current Sequence Value
Get Next Sequence Value
Using a Sequence in a Table Column