How much of an impact will setting up/running a Minecraft server have?

I want to create a server for a few friends and I. I'm wondering if it will slow down the internet for other people in my house when its on. Also, can you explain the RAM usage of a Minecraft server for me? I can simply turn off the server and I will have my full RAM, right?

Running a Minecraft server will impact your internet speed, but only when it is running, and not severely. Minecraft servers need a good amount of RAM to work properly, but you can decide how much you want to use in the server settings. Your RAM, however, replenishes itself, so your computer will most likely not be impacted EXCEPT for when the server is running. When you turn off the server, your RAM goes back to normal, and it will never go down over time. The only thing that I would say that is really impacted by a Minecraft Server is your time. It takes a good deal of time to port forward your router, then set it up to your liking. If you only want a small server with a group of friends, you should be fine. To manage a full-on user server will take a lot more time. If you have any other questions about Port Forwarding, or configuring of your server, please message me, and I will be happy to help.

Cheers!
~TheJavaWalkie