SAP ABAP (Advanced Business Application Programming) is a programming language used by developers to create custom applications and modifications within the SAP system. ABAP developers work on the technical side of SAP and are responsible for designing, implementing, and maintaining the technical aspects of SAP systems.

On the other hand, SAP consultants are professionals who provide expertise in various functional areas of SAP, such as finance, sales and distribution, human resources, logistics, and supply chain management. SAP consultants work with clients to understand their business processes and requirements, and then provide recommendations on how to configure and optimize the SAP system to meet those needs.

In summary, SAP ABAP developers work on the technical side of the SAP system, while SAP consultants work on the functional side, providing expertise in specific areas of the SAP system.