In reply to haithamx15:
You seem to be confusing a sequence_item and a sequence.
A sequence_item will contain all of the information that the agent needs to complete a transaction. This typically includes the target address, read/write designation, data, multi-beat (burst) parameters, transaction delays, etc. The sequence_item will allow you to specify any type of transaction that the master can conduct.
The driver will ‘translate’ the sequence_item into DUT pin ‘wiggles’.
Please read this article which will help you understand what a sequence_item encapsulates.
A sequence will co-ordinate the generation of multiple sequence_items. This may entail a write followed by a read, many different write/read transactions, etc.