SAP HANA XS is stands for SAP HANA Extended Application Services. Sometimes it is also referred as XS Engine or just XS. The main idea of SAP HANA XS is to embed a full featured application server, web server, and development environment within the SAP HANA appliance itself. XS is not a completely separate technology that happens to be installed on the same hardware server as SAP HANA. The rationale for XS is mainly twofold: simplicity - enable SAP HANA-based application development and deployment while minimizing architectural layers; and performance - tight integration with the SAP HANA DB ensures optimal performance.  With XS, you have the ability to create applications that have an http-based end-user UI (e.g., browser, mobile apps), which run directly on SAP HANA, without additional external servers or system landscape components.