SAP Extension Suite gives you the services, tools and capabilities to build and maintain extensions to your business apps in the cloud. Use it when you need to implement additional processes on top of your existing SAP applications.
The Business Technology Platform, or BTP for short, is a cloud-based PaaS (Platform as a Service) offered by SAP. The BTP provides application developers with a canvas where they can create applications and extensions to suit their customers customization needs.
AMDPs provide powerful abstractions that enable ABAP developers to combine the benefits of the high-speed in-memory execution of SAP HANA with the well-established ABAP runtime and lifecycle model. Along with CDS Views, CDS Table Functions, and OPEN SQL, allow ABAP developers to renovate their existing assets and create new and innovative applications for SAP Business Suite on SAP HANA without losing the platform-independence of ABAP.