A metal mount is generally superior to a plastic mount as it is more durable.
The device is protected with extra seals to prevent failures caused by dust, raindrops, and water splashes.
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 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.
A prime lens has a fixed focal length. In general, these are sharper, with a wider aperture.
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.
The front element doesn’t rotate. This is important if you use filters, as some such as polarising or gradient filters have to be orientated a certain way.
The lens hood can screw onto the lens in reverse so that you can keep it on your camera at all times, ready to use.
A macro lens is used to take very close-up photos, allowing you to capture flowers, insects etc. in great detail. A macro lens is any lens with 1:1 magnification.