If you have looked at any camera online, you have probably seen the words X times "Digital Zoom" or X times "Optical Zoom." Most people ignore the first word and simply think of them both as a zoom, but it's about time you know the difference since the difference is HUGE!
Digital Zoom is the equivalent of taking a max resolution picture, cropping into it, and then scaling back up to the max resolution. What you are left with is a lower quality image that is "zoomed" in. While the image may look fine when viewed on a smaller device such as a phone or tablet, it will never be as sharp as taking a full sized image.
Optical Zoom, on the other hand, occurs when the optical glass in your lens adjusts to actually zoom in on your scene. The result is a max resolution, high quality photo.
Sadly all smart phones currently use digital zoom which is why your zoomed in shots never look that great and always seem a bit blurry. A few attempts have been made to make a smart phone/camera hybrid with Optical Zoom, but they all failed.
In the end, go with Optical Zoom or just don't zoom in with your Digital Zoom camera.