There are so many high-quality videos on YouTube that are worthy of downloading for collection or need to be downloaded for enjoyment later due to poor Internet connection speed. There are usually 4 approaches to do this:

1. Online tools: it's efficient and simple, without downloading and installing; but their function is simplex, and only supports a few resolutions;
2. Browser plug-ins: it has similar pros and cons with the former;
3. Desktop software: it requires downloading and installing software, with relatively powerful functions;
4. Command lines: very powerful, but requires some prior configurations, and difficult for beginners to use.

YTD Video Downloader (AKA: YouTube Video Downloader) is a universal professional web video direct downloading tool with simple, intuitive UI & using method. It's original name is YouTube Video Downloader, from which we can see that it was specifically designed to download YouTube videos at first. Of course, following the increase of supported video websites and functions, also considering SEO, it changed its name.