This is one of the most asked questions in google.
But the answers include many shortcuts and paid softwares like 4k-video-downloader
Now I am using a software which is open source and free to download without any restrictions.
It started as a command line tool for downloading youtube videos, now it supports many sites.
Note: A link to supported sites is here
This blog is a simple tutorial about how to use it without doing much google search
First of all,
When downloading an entire playlist its better to have auto-increment option in the software.
playlist-index will add indexes accordingly to the video
But there is customize this too, using the Format tab in Options
Subtitles are one of the important features while watching videos, so diverse group of people benefit from the content of the video, even though they don't understand content creators' language
You can download subtitle language(s) of your choice, if you need you can embed it too(only on mp4 videos) !!!
Sometimes internet will be down and the software don't have a resume option,
But there is something else available
When you use
-c or --continue
combining with the index of the video
to continue from where you left off
Youtube-dl-gui is very helpful for me. But no great beginner posts available.
Hope it helps!!!!