Reactive Forms

Two options to build forms in Angular:

• Template Driven Form

• Reactive Form

Template Driven Form

• Its the default option to build forms in Angular

• It uses Angular provided form template directives to build forms

Reactive Form

• We create the model objects of the Form elements in the component code, thus these are also known as model-driven forms. There is very minimal form template in the HTML

• advantages:

  • js object driven form fields and their validations

  • dynamically validate and generate the custom validation messages for the form fields

  • easily unit testable

Read in Details

https://medium.com/aviabird/complete-angular2-guide-reactive-forms-in-depth-part-1-21a8e2428904