A. executionTimeout attribute of httpRuntime element (web.config): ASP.NET will timeout the request, if it is not completed within “ executionTimeout ” duration value. And System.Web.HttpException: Request timed out exception will be thrown by ASP.NET Application. executionTimeout attribute of httpRuntime element (in the web.config) can be used to change the request timeout duration for ASP.NET Application. executionTimeout value is specified in seconds. Default value is 110 seconds. <configuration> <system.web> <httpRuntime targetFramework= "4.5.1" executionTimeout= "500" /> </system.web> </configuration> B. timeout attribute of sessionState element (web.config): If the user remains idle for duration specified in timeout attribute vaule of sessionState element (in web.config) , then his session will expire. timeout attribute of sessionState element (in the web.config) can be used to change session tim