Html.BeginForm has some parameters,
ActionName – Name of the Action.
ControllerName – Name of the Controller.
FormMethod – The Form Method i.e. GET or POST.
htmlAttributes - An object that contains name/value pairs.
If you leave it empty, it will look for a Post action with the the name of the page you are currently.
Example:
If you are in on the Index page, it will look for a Index Post action.