Explanation
To enable the system to check the shelf life of materials at goods receipt, you must meet the following prerequisites:
The purchase order item contains the remaining shelf life, which is the minimum number of days that a material must be usable after goods receipt.
The shelf life expiration date check is activated for the movement type in Customizing, which means that the system will compare the remaining shelf life in the purchase order with the total shelf life in the material master and reject the goods receipt if it does not meet the requirement. References: SAP S/4HANA Sourcing and Procurement | SAP Learning, Course S4510, Unit 2, Lesson 1.

Explanation
When you post a goods receipt to stock with reference to a purchase order, you can perform the following actions:
Split the quantity received to multiple storage locations, which means that you can distribute the goods receipt quantity among different places where materials are physically stored within a plant.
Post partial order quantity, which means that you can receive multiple partial deliveries for the same purchase order item. References: SAP S/4HANA Sourcing and Procurement | SAP Learning, Course S4510, Unit 2, Lesson 1.

Explanation
A document type in purchasing is a classification of purchasing documents (such as purchase orders, contracts, requests for quotation, etc.) that defines some basic characteristics and controls for each document. Some of the aspects that you can control with a document type are:
Reference to purchase requisitions, which means that you can specify whether a purchasing document can be created with reference to a purchase requisition or not.
Number range, which means that you can define the number interval and the number assignment (internal or external) for each purchasing document.
Item number interval, which means that you can define the increment and the length of the item numbers for each purchasing document. References: [SAP Help Portal], [SAP Help Portal], [SAP Help Portal]

Explanation
The account category reference is a grouping of material types that have a similar account determination. By assigning the same account category reference to different material types, you can control that they use the same valuation class for account determination. The valuation class is a key factor that determines which general ledger accounts are posted during inventory transactions. Therefore, if you want to set up the same account determination for raw materials (material type ROH) and operating supplies (material type HIBE), you can group them by assigning the same account category reference to these material types.References:
[SAP Help Portal], [SAP Help Portal]

Explanation
When creating a value contract with a supplier for packaging, you must use the item category W (Material group). This item category allows you to specify only a material group and a target quantity or value without specifying exact materials and their purchase prices until the release orders. You cannot use the item categories B (Limit), T (Text), or M (Material unknown) for this purpose.References: [SAP Help Portal - Value Contract]