Sales Order Cycle constitutes one of the most important components of the SAP SD module. A Sales Order is an agreement between an organization to sell products / services over a specific period of time in certain quantities. In SAP SD, a sales order takes information from the customer master record and material master record. The Sales Order process would look like

Quotation >> Sales Order >> Delivery >> Invoice

SAP offers some unique feature with sales orders. A sales order can be created with reference to a preceding document, such as a quotation. All data from the quotation is copied into the sales order. This data in turn gets copied to the delivery document creating a delivery note. Once the goods issue is made, information can flow to billing. One thing I have noted is that SAP offers flexiblility accross modules. This helps since master data is required to be created only once and the transactional entries can follow.

More on SAP SD >>

Defining Sales Organization , Assigning Sales Areas to Sales Documents , Sales Documents , Blocked SAP Sales Orders