Authentication in forms is added in order to include a layer of security to access the user for a specific service. This authentication is done by verifying the user’s identity through the credentials such as username with password or email with a password.
The code snippet will look something like this:
<system.web>
<authentication mode = "Forms" >
<formsloginUrl = "Login.aspx" protection = "All" timeout = "30" name = ".ASPXAUTH" path = "/" requireSSL = "false" defaultUrl = "default.aspx" cookieless = "UseDeviceProfile" />
</authentication>
</system.web>