How to set session timeout in web.config?

Here I am explaning how to set session timeout in web.config.

if we want to set our custom timeout in our applications we can set it

in web.config.  we can set timeout session in

<configuration>à under <system.web>

  
<configuration>
<system.web>
<sessionState mode="InProc" timeout="20">
</sessionState>
</system.web>
</configuration>