Just started using Plex—noob question: Can I still use my laptop (server) while Plex is being used on the TV?

I'm a new member of Plex. I’m using my laptop as the server—can I still use my laptop while running the server? I was streaming a high-quality YouTube video on my laptop, but at the same time, Plex on my TV was struggling to play videos smoothly.

When I downgraded the YouTube video to 240p and restarted Plex on the TV, it started streaming smoothly, at least for now. Is there a workaround if this is the issue?