What is the purpose of FormBuilder?

FormBuilder is used as syntactic sugar for easily creating instances of a FormControl, FormGroup, or FormArray. This is helpful to reduce the amount of boilerplate needed to build complex reactive forms. It is available as an injectable helper class of the @angular/forms package.

For example, the user profile component creation becomes easier as shown here.

export class UserProfileComponent {
  profileForm = this.formBuilder.group({
    firstName: [''],
    lastName: [''],
    address: this.formBuilder.group({
      street: [''],
      city: [''],
      state: [''],
      zip: ['']
    }),
  });
  constructor(private formBuilder: FormBuilder) { }
  }