In Data Processing, the term SAP stands for Systems Applications and Products.SAP by definition is also named of the ERP (Enterprise Resource Planning) software as well the name of the company. In SAP, materials Management module there are several components and sub-components that exists like Master Data, Inventory, and Purchasing.
If you want to learn SAP MM from scratch, then here's the right video for you:
If you are more into reading, then do check out this material provided by Intellipaat:
There's a wide scope for SAP MM consultants in companies that deals with real estate, manufacturing automobiles and so on. As a fresher, you can get started with SAP MM module.