There are many points of integration between mm and both FICO and SD. However, MM deals with stock purchase and storage and the main POI with FICO is therefore Accounts Payable (there are others such as customs excise duty, tax, stock valuation, etc). 

MM is where the stock sold through SD is controlled. The Materials MASTER data, in which details of each item of stock is created and maintained, stock levels, etc is used in SD transactions to identify the goods or services being sold, how many are available and from where.

An item category defines the characteristics of an item. Which characteristics ar taken into account differs between modules. e.g. in MM - material number, goods receipt, invoice receipt, etc: in SD - Pricing, BILLING, delivery, etc.

An item category GROUP, groups a variety of items together for accounting/stock control purposes.

A Pricing procedure governs the price applied to a material. It might take into account cost, discount, surcharge, freight, and tax. A Tax procedure determines the type and amount of tax that is applied and might vary according to the type of item e.g. food might have a different tax category COMPARED to an automobile, fuel for domestic heating might be taxed differently from fuel for cars.

There are many points of integration between mm and both FICO and SD. However, MM deals with stock purchase and storage and the main poi with FICO is therefore Accounts Payable (there are others such as customs excise duty, tax, stock valuation, etc). 

MM is where the stock sold through SD is controlled. The Materials master data, in which details of each item of stock is created and maintained, stock levels, etc is used in SD transactions to identify the goods or services being sold, how many are available and from where.

An item category defines the characteristics of an item. Which characteristics ar taken into account differs between modules. e.g. in MM - material number, goods receipt, invoice receipt, etc: in SD - Pricing, Billing, delivery, etc.

An item category Group, groups a variety of items together for accounting/stock control purposes.

A Pricing procedure governs the price applied to a material. It might take into account cost, discount, surcharge, freight, and tax. A Tax procedure determines the type and amount of tax that is applied and might vary according to the type of item e.g. food might have a different tax category compared to an automobile, fuel for domestic heating might be taxed differently from fuel for cars.