When designing an UI, we need to target many android mutations and various screen resolutions.
If you build your views using "dp" it would, basically, be the same size for eack screen size.
In most cases you will prefer that your view will resize itself proportional to the screen size.
Of course, in most cases you will need to build separate layouts for tablets.
But, besides I can recommend you to do the next steps:
1. Add this library to your project.
2. Now in your layout you can write views like that:
In this example your TextView will scale on each screen size.