Control classes and directive

In angular we have two classes to keep track of the state of input fields and their validity
Formcontrol which represents one input field
When we apply ngModel directive on the input field angular automatically creates a formcontrol object and associates that with the input field
Formgroup which represents a group of input fields
Used to represent a entire form and optionally groups within the form
ngForm is applied automatically to all form elements and creates a form group object and associates with the form. It tracks the state changes of form and their validity.
When you have complex form with mulitple subgroups, you can optionally apply ngModelGroup directive on subgroup creates a form group object for that sub group
ngForm exposes output property ngSubmit which is used to handle submit events of form, ngModelGroup doesn't

Angular