Introduction of SAPUI5 technology:
SAPUI5 comes with all of the features needed to cover most current application requirements such as Full translation Support, built in extensibility concepts at code and application level, keyboard interaction. Last but not the least, it also uses the open source jQuery library as a foundation
Applications built with SAPUI5 are responsive across browsers and devices – they run on smartphones, tablets, and desktops. The UI controls automatically adapt themselves to the capabilities of each device.
If you wish to take a deep dive at OpenUI5, an open source version of the UI development toolkit for HTML5, it is available at http://openui5.org/
What is Sapui5 ?
The UI development toolkit for HTML5 (SAPUI5) is a platform for developing rich user interfaces for modern Web business applications.
Servers come into play for deploying your applications, storing the SAPUI5 libraries, and connecting to a database. Depending on the environment in which you are using SAPUI5, the libraries and your applications are stored for instance on an App Server or an HANA Cloud Platform. The preferred way to access business data for your application is by using the OData model through an SAP Gateway.
When users access an SAPUI5 application from their device, a request is sent to the respective server to load the application into the browser. The view accesses the relevant libraries. Usually, the model is also instantiated and business data is fetched from the database.
Depending on the platform your SAPUI5 applications runs on, different browsers in different versions are supported. If you know the platform and the browser used by your users, you can decide on the libraries you use for your application.
Whether you develop a SAPUI5 application for desktop or for mobile, the concepts are very similar. SAPUI5 provides an additional control library called sap.m, which is optimized for mobile devices, but also runs fine in desktop browsers.
In my opinion, while building UI5 apps, careful approach need to be taken in order to avoid ambiguity among diversified structures that get created. It is ideal to follow the design principles illustrated by SAP for developing Fiori apps.