system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does watching flash videos/streams in Google Chrome slow down other tabs?

AFAIK Google Chrome runs each tab in a separate process. So if something hogs one tab, other tabs remain responsive.
Why is it that watching twitch streams slows down my other tabs. For example it's especially noticeable when twitch.tv is open in one tab and i'm scrolling down reddit in another tab.

When i use another browser to stream twitch then Google Chrome tabs remain responsive.
gpt
I first had a very technical explanation which was very hard to understand i will now try it with an analogy.

Imagine your computer is a supermarket and every CPU core is check-out. Every customer is a process and the things they buy are the commands which every task needs to execute. If a task like the twitch tab needs to execute many commands it can block the check-out for longer therefore other processes need to wait longer and feel slower.

One of the techniques to mitigate this problem (so that one process can't hog the CPU core for to long) is scheduling.  
It works by setting a limit on how much goods at a time can be checked out so that other processes get some time as well.

I hope this makes things a bit clearer and feel free to ask questions and i try to answer them as good as i can.