About Third Party Sale

Dear Gurus,

Kindly help me with configure the below process.

Unlike a third pary item ,which is delivered to the customer directly by the vendor, I want to add a material in the sales order which is procured and placed in stock, schedule lines allowed and then delivered along with other items. Which settings would make this material behave differently from a third party item.

Also, could you please tell me the difference between TAS and TAB Item categories?

Many Thanks

Kumar