Loading and initializing SAPUI5 in your HTML page is required to use SAPUI5 for your application.
You can use the SAPUI5 bootstrap script in your page to initialize SAPUI5 runtime automatically as soon as the script is loaded and executed by the browser. For simple use cases as well as the default SAPUI5 installation, this is sufficient to build and run UIs. In addition to this, you can specify the set of SAPUI5 libraries and the theme used for your application in the configuration settings.
The following code snippet shows a typical bootstrap script tag:
The attributes data-sap-ui-theme="sap_bluecrystal" and data-sap-ui-libs="sap.ui.commons" already provide examples of how SAPUI5 runtime can be configured to the needs of an application.