Difference beween FormCollection and Model binder in MVC

https://www.c-sharpcorner.com/forums/difference-beween-formcollection-and-model-binder-in-mvc 

Model binding maps data from HTTP requests to action method parameters. Parameters may be simple types such as strings, integers, or floats, or they may be complex types which os model class.

 

In Form collection you will be able to get all the values inside the form as model binder. but There can be situations where you may need to pass some additional values from the form which may not be part of your model class. suppose you have 10 properties in your model class which render controls on the view plus you added 5 hidden fields extra, form collection will get those values also