in sap ui5 architecture, you have three layers −

• at the top, is the presentation layer, where ui5 components are consumed by devices like mobile, tablets, and laptops.

• at the middle layer, is the application clients that includes sap ui5 libraries for theming and control. ui5 control libraries include

  • sap.viz

  • sap.ui.commons (controls like text fields and buttons)

  • sap.ui.table (input controls for table)

  • sap.ui.ux3

  • sap.m (includes input control for mobile devices)

• at the bottom, is the option server component. this includes sap netweaver application server for abap/java, sap backend, hana xs engine for development or database.