What does the 18-200 lens mean?

The focal length can be freely changed from 18 mm to 200 mm, so-called "traveling around the world" and "traveling head". In order to ensure that all focal lengths can be used, compromises were made, so the imaging quality is average, but the price is expensive, around 4,000. Generally used on APS frame bodies, ensure there is a wide-angle end. Full-frame bodies generally don’t use lenses with this kind of compromise.

If you don’t have high requirements for photography and just take photos for fun, this is a suitable option. After all, you can travel all over the world with one lens, including landscapes and telephotos. If you have high requirements for photography, or want to further improve your photography in the future, it is recommended not to consider this option, because its price is high and it will become a "tasteless" option for you.