It's not mining. It's not staking. It doesn't slow down your computer (much). It's loaning your CPU to do video encoding.
I am running the Theta Edge Node (download here) on an old laptop from 2011 running Windows 7. The CPU is an Intel Core I7-3540M.
After downloading the Theta Edge Node Windows app (also available for MacOS), I started the app. No configuration was necessary. The Theta Edge Node creates a wallet for accumulated earnings.
I left the laptop running in my office, off to the side, since it wasn't being used for anything else.
Nothing appeared for the first day or two, then jobs started coming in at random intervals. The jobs were all video encoding tasks. Each paid between 0.09 and 0.11 TFUEL.
After several days, the Theta Edge Node was earning between 0.5 and 1.0 TFUEL each day. I don't know how their algorithm picks which Edge Node to use, but I suspect it is related to how long the Theta Edge Node has been running: the longer the uptime, the more likely to get a job.
TFUEL are accumulated in your account (not a wallet) and then paid out to the automatically-created wallet during the first week of the month. However, the payout is only made if the accumulated balance is greater than 3.0 TFUEL. One note: I think there is a bug in the payout code: if your accumulated balance is less than about 6 TFUEL, you will be left with about 3 TFUEL and the rest lost. In other words, you need more than 6 TFUEL to avoid losing any and your wallet will receive your accumulated balance minus 3 TFUEL.
The left side of the window shows "Available balance", which is the automatically-created wallet; and "Edge earnings", which is the current accumulated balance.
I usually wait until I have more than 50 TFUEL in the automatically-created wallet before transferring it to my own self-custodial wallet (Exodus). There is a 0.3 TFUEL fee for withdrawing. Eventually, I will trade it for Bitcoin (BTC) or Ethereum (ETH), unless I see TFUEL more widely adopted.
On the other hand, if you get more than 10,000 TFUEL in your automatically-created wallet, you can stake your TFUEL for addition earnings.
Once you have your Theta Edge Node earning TFUEL, you can click on WATCH and watch streams for more TFUEL. You might have to leave the stream running a long time (a day or so) to earn any TFUEL.
A command-line interface (CLI) version of the Theta Edge Node is available for Linux. However, I could not get the monitoring interface to show me if it was actually earning anything, so I turned it off. I may revisit it later if the Theta team makes some improvements to the CLI version.
TFUEL can also be earned on the Theta.tv website without the Theta Edge Node running.
Of course, this is not financial advice. Do Your Own Research (DYOR) to see if this works for you