> To store the connection strings at a place, configuration files are used in .net application. > We use web.config file for web application and app.config file for windows application. WEB.CONFIG:- • It’s a configuration file for web application. • This file is used to store the connection string which contains the code for the connectivity with the data source. • This file is added by default if we are developing ASP.NET web application. • The extension of a configuration file is .config . • A configuration file can store multiple connectionStrings . APP.CONFIG:- • It’s a configuration file for windows application....