Letter of Credit and Drawing

Dear All,

Could you please explain me, What is the different of Letter of Credit and Drawing?
And Please tell me the flow of them, How are they created?

Thanks

TF (trade finance) in T24 got 3 main applications, they are LC (letter of credit), LC.AMENDMENTS and DRAWINGS.
LC: Store, maintain, manage all information on LCs, and Collection.
LC.AMENDMENTS: for external amendments which requires Ben's consent only. After approving amendments, they will be updated into LC records, otherwise they will not.
DRAWINGS: used for payment of collection and/or for registering/refusal/acceptance/payment of LC documents. Drawings ID = LC ID + XX (where XX = sequence number), therefore Drawings transactions are only handled/processed with existing LC ID.

Thank alots Dust.