SAP
SAP stands for Systems, Applications and Products in Data Processing. It is also the name of the corporation that constructed the Enterprise Resource Planning (ERP) system of the same name.
Large and medium size corporations use ERP systems to make sure their business processes are effective and efficient.
The purpose of an ERP systems is to map the business processes such as finance, production planning, sales and distribution, material management and other onto a digital landscape.
SAP modules
SAP is divided into modules. Each module covers a single business process such as Finance(FI), Material Management(MM) or Sales and Distribution(SD).
SAP development and customization
Businesses have very similar processes which is why they are already implemented as programs in SAP modules.
However, each business wants these modules fine tuned to their specific needs.
The programs are fine tuned using the SAP Implementation Guide (IMG). Unfortunately, some business requirements are so specific that the only way to implement them is to use a programming language called ABAP to construct a brand new program.
ABAP
ABAP stands for Advanced Business Application Programming, a programming language similar to COBOL.
SAP is almost exclusively written in ABAP.
Learning ABAP is quite difficult due to a lack of pedagogically sound, free tutorials. This is partly why I've decided to create this repository.
Other tools
SAP comes with a large selection of programming tools such as an Integrated Development Environment (IDE) of its own, graphical document editor called SmartForms, tools that allow SAP to connect and communicate with other system called ALE as well as a testing suite like eCATT.