Major difference between Form Authentication and Windows authentication in asp.net

Forms Authentication

Forms Authentication is a process to allow only authenticated user with valid credential to view a particular page or group of pages/folders and stop unauthenticated or anonymous user outside the secure boundary.

Its mainly to protect the particular folder or page from the group of user or particular user. Form authentication stores all the user details inside a cookie.

User details consist of the User roles, User name. However the page is disable cookies function, then it works by passing all the values in Query string.

Windows authentication

Windows authentication is the default authentication method of the ASP.NET application. Windows authentication it will use local windows user and groups to do authentication and authorization for your ASP.NET pages.Web application can use the same security that applies to your windows application which will authenticate to your window like user names, passwords, and permissions. Mainly used for intranet application.

In order to use windows authentication, you need to make sure your web application's hosting and client user's machine meet the requirements. Generally, both the client and server machines should be in the same local network environment, and they should be part of the same Windows domain (or trusted domain).