When you create a sales order you can select an Order Type (SalesType). There are a few options here
You can use a journal as a draft sales order. While can you add sales lines you won’t be able to confirm, ship, invoice. As well the order won’t be picked up in master planning. Some customers have used a journal as a review status for example when importing sales order or bringing them in from an integration. When the order is ready to execute then you can change the order type on the sales header.
A subscription is a handy type if you sell, ship, bill the same thing often to the same customer. You can do all the same functionality that you will do when the type is sales order but when you invoice then the order status will be set back to Open Order.
A sales order type is going to be the most common type selected as it give the most common functionality for selling goods to communicate to the customer from confirmation, through ship and invoicing. While you might do all the processes from this form for example if using warehousing the shipping will be done from over there.
When creating a sales order you won’t be able to select return order manually. This is used when you create a return order from the return order forms.
You won’t be able to select item requirements manually. This is a status given to a sales order when it’s created as an item requirements associated with a project in project accounting.
If you look into the table (SalesTable) this is represented by the field SalesType which is an enum of the same name. In R3 you will see the options listed above but in earlier version of AX there were additional options which were quotation and Blanket.
Quotation are handled as a different document in the SalesQuoationTable and has it’s own status which is QuotationStatus on this table.
Blanket is a concept that you can handled with the sales agreement where you do releases from the agreement or handle with the subscription type order.