With the WebRole element you define your web application. The only requirement is the ability to run the application on IIS 7 or higher.
Typical examples for this are applications based on ASP.NET (ASP.NET, ASP.NET MVC, and so on), PHP, Windows Communication Foundation, or FastCGI.
A template of a WebRole element looks as follows:
<ServiceDefinition ...>
<WebRole name="<web-role-name>" vmsize="<web-role-size>"
enableNativeCodeExecution="[true | false]">
<Certificates>
<Certificate name="<certificate-name>" storeLocation="
<certificate-store>" storeName="<store-name>" />
</Certificates>
<ConfigurationSettings>
<Setting name="<setting-name>" />
</ConfigurationSettings>
<Imports>
<Import moduleName="<import-module>"/>
</Imports>
<Endpoints...