angular reactiveform, templateform and dynamicform
Yeap if you have the feeling these are all different methods used in constructing forms, then you're right.
ReactiveForm - uses reactive style to work with form. It would uses reactive way to monitor, track interaction with the forms. To work with this you need to use FormGroup to create a series of control for your form or just FormGroup an individual element to tied to your HTML control.
Please take a look at this to get an idea of how reactive form works.
TemplateForm - uses the model and HTML approach whereby HTML tags are binded to a model
DynamicForm - an approach that lets you create forms dynamically and faster by using ReactiveForm and cleverly using OO strategy to make sure questions are rendered dynamically.