We consider a lower weight better because lighter devices are more comfortable to carry. A lower weight is also an advantage for home appliances, as it makes transportation easier, and for many other types of products.
A metal mount is generally superior to a plastic mount as it is more durable.
A prime lens has a fixed focal length. In general, these are sharper, with a wider aperture.
A shorter minimum focal length allows you to get more of the scene in the photo, and offers a wider angle of view than longer focal lengths.
A longer maximum focal length allows you to focus in on a small part of a scene, and offers a narrower angle of view than shorter focal lengths.
It comes with a lens hood so that you don’t have to buy it separately. These are used to block strong light sources, such as the sun, from the lens to prevent glare and lens flare.
A telephoto lens allows you to zoom in on far away objects. This is particularly useful when you need to photograph a subject from a distance, such as wildlife photography, or even in some cases street photography where you can’t get near the subject.