Guys, I need help with something...please

Here's a question- if I'm watching a show and I see something in the show and I want to share say a 20 second clip from that show and post it in a forum for discussion, how can I do that.
I'm thinking it's something like finding the same show on YouTube and then there has to be some kind of option to cut or edit that bit out so I can share it, right?
I took a screen shot but people will probably want to analyse it, so I want an actual segment I can post...
If anybody has done this I would appreciate it. I was sure other people would've seen what I saw and so I googled it up but even though there are whole sections of the Internet dedicated to this particular topic no one has...
Please and thank you in advance 🙂

@aquanib
@Alpha
@tiziani

cheers for the info guys, I'll check out the options.
😎