While defining and developing web  applications one important thing that you have is the configuration file that contains the information and settings of your applications.

This is the basic structure of your configuration file.
 

<configuration>

   <!-- Configuration section-handler declaration area. -->
      <configSections>
         <section name="section1" type="section1Handler" />
         <section name="section2" type="section2Handler" />
      </configSections>
   <!-- Configuration section settings area. -->
   
   <section1>
      <s1Setting1 attribute1="attr1" />
   </section1>
   
   <section2>
      <s2Setting1 attribute1="attr1" />
   </section2>
   
   <system.web>
      <authentication mode="Windows" />
   </system.web>
   
</configuration>

Configuration Section Handler declarations

• Clear - It removes all the references.

• Remove - It removes inherited section

• Section - It defines association between handlers.

• Section group - It defines association between the groups defined.

Application Settings

It will define the settings associated with your project.

<configuration>
   <appSettings>
      <add key="Application Name" value="MyApplication" /> 
   </appSettings>
</configuration>

Connection Strings

It defines all the details that is used to build connection with the database or the datasource .

<connectionStrings>
   <add name="ASPDotNetStepByStepConnectionString" 
      connectionString="Provider=Microsoft.Jet.OLEDB.4.0;
      Data Source=E:\\projects\datacaching\ /
      datacaching\App_Data\ASPDotNetStepByStep.mdb"
      providerName="System.Data.OleDb" />
      
   <add name="booksConnectionString" 
      connectionString="Provider=Microsoft.Jet.OLEDB.4.0;
      Data Source=C:\ \databinding\App_Data\books.mdb"
      providerName="System.Data.OleDb" />
</connectionStrings>

Anonymous Identification

It defines the authorization and the authentication  section used for providing login and passing to the proper role page.

<authentication mode="[Windows|Forms|Passport|None]"> 
   <forms>...</forms>
   <passport/>
</authentication>


<authorization> 
   <allow .../>
   <deny .../>
</authorization>