Spiders come in many shapes and sizes. Some spiders are well known and some are seen as a threat. Without spiders, the population of many annoying bugs would be larger. As long as they are not bothered, spiders don't pose a serious threat to most animals or people.
One type of spider is the crab spider. Crab spiders do not spin webs, they use their venom to kill their prey. Crab spiders are no bigger than a bee but are able to kill insects larger than themselves.
Another spider is a tarantula. Tarantulas are well known around the world. They are the giants of the spider community, but they cause no harm to humans. Although they have big fangs, their bite hurts only as much as a bee sting. Tarantulas will not bite unless they feel threatened or are stressed.
From Australia, widow spiders (also called red-black spiders), are named after their color. Unlike the tarantula's bite, the female widow spider's bite is deadly. Male widow spider's fangs are too small to harm humans. Always stay away from widow spiders if you don't know whether it's a male or female.
It is interesting to learn about spiders. There are many more species of spiders than these three to study, and there are probably even more spiders that are yet to be discovered.
[Source: the big bug book]