There are so many ways to download Youtube videos today. The first one that I used before was through IDM or Internet Download Manager. Just installing IDM and integrating it with your browser will automatically detect a Youtube video that you will play and will provide you the download link.
How to download Youtube Videos using your VLC player

Another way is using so many online websites like the list below.

https://www.onlinevideoconverter.com/youtube-converter
https://www.converto.io/en
https://youtubemp4.to

The website links given above allows you to just copy a Youtube video link, and then paste it on their website. They will automatically convert the video to either mp4, avi, or whatsoever kind of extensions they have there. After the conversion if successful, then, they will also provide the download link and all you have to do is download the video.

For this article, you are going to use your installed VLC player to download a Youtube video. You will be going to need the following:

NEEDED:

1. VLC player installed in your laptop/desktop computer. If you do not have one, download VLC here. After downloading install it.

2. And the link of your Youtube video (e.g. https://www.youtube.com/watch?v=7UnyaQt9Dt4)

STEPS:
1. Open your installed VLC player. Click Media > Open Network Stream... See photo below.


2. In the Network tab, you will see the "Please enter a network URL:" paste your Youtube video link there and hit the "Play" button.


3. Wait for the video to play. While playing, go to Tools > Codec Information.


4. Inside the Codec tab, you will see at the bottom the exact link of the Youtube video. Copy that link.


5. After copying the link, open your internet browser and paste the link you copied from VLC in the address bar.


6. When you pasted the link, press the Enter key on your keyboard.


7. The video will now play, right-click the video and then click "Save video as.."


8. Select the location where you want to save your Youtube video, then press the "Save" button.


9. Now, you are downloading your Youtube video. Just wait for it to finish.


That's a little tricky tutorial, but when you get used to it, it is very easy to do as long as you have your VLC player installed. Or if you do not want to download the video and just going to play it, I think it is better to play your Youtube video using VLC for less CPU usage.

You can also consider watching the Youtube video that I created on how to download Youtube videos using your installed VLC player, just click the play button to start watching.