[()] indicates two-way binding. If you curious you can read more in docs [1], while ngFor is just an attribute directive which changes DOM [2] [1] - https://an

[()] indicates two-way binding. If you curious you can read more in docs [1], while ngFor is just an attribute directive which changes DOM [2] [1] - https://angular.io/docs/ts/latest/guide/template-syntax.html#!#two-way-binding-with-ngmodel https://angular.io/docs/ts/latest/guide/template-syntax.html... [2] - https://angular.io/docs/ts/latest/guide/attribute-directives.html https://angular.io/docs/ts/latest/guide/attribute-directives...