Snakes are amazing creatures. We'll start with venomous snakes. Cobras are the most famous snakes. They have hoods like this:
They will rise to strike and defend. but vipers would start low and strike high up at attackers and prey. On the other hand, constrictors like pythons, anacondas and boa constrictors would squeeze their prey to death (there is a picture of a rock python in this blog's introduction).
Say you see a snake about a foot long--you don't have to worry. Most of the world's snakes are almost harmless to humans. Yet the hognosed snake has a hood, but it is harmless.
Yes, snakes are amazing!