system
Given the following post, respond as if you're commenting on Reddit:
human
LI5: What is plasma?
gpt
It's a state of matter.

Matter is something like metal or plastic or sand or rock or water or steam.

The state of matter means whether it's solid, liquid, gas or plasma.

Plasma was only recently discovered. It's basically superheated gas.

For example, let's look at ice. Ice is a solid, but when you heat it up, it melts, and is a liquid. When you heat this liquid ice - we usually call it water - up to 100 degrees Celsius, it boils, and that stuff you see coming off of the top of the water is steam. That's the 3rd state of matter, gas. If you were to collect that steam and heat that up, you'd turn it into plasma, the 4th state of matter.

Plasma is present in neon lighting (running electricity through basic gases, heating them and causing them to emit coloured light) and in plasma TVs.