YouTube is designed to keep users active within their ecosystem, and videos are property of the creator and YouTube according to their licensing agreements. Viewers are not allowed to download videos directly, and you should only proceed with a download or video-saving process when you either own the video or have permission from both the creator and YouTube. Otherwise, you're violating their copyright and creating an illegal download. This means you must either purchase the video for offline use on a USB or contact the creator for permission directly. Without a dedicated downloading option available, you'll need a conversion program or a recording program to grab the video as it plays on your screen.
YouTube to USB Converter
The simplest and most effective means to copy YouTube video is through a YouTube to USB converter. These custom software programs are deigned to save published YouTube videos as media files on your computer or a USB-connected external flash drive. A 4K video recorder will download by simply pasting the video URL into the software. A simple Google search will yield a number of programs made for this specific application. Ideally, you can find a program that works inside a web browser. Avoid downloading software to your hard drive unless you trust the source and the download is an absolute necessity. Otherwise, locate a program that will convert YouTube videos to media files, and then save the file to your USB drive.
Screen Recorder
Screen recording programs are another method of pulling YouTube videos into an external media file for download. Numerous screen recording programs are available. Make sure to choose one that records everything happening on the screen along with audio. Many recording programs are designed to capture your screen for tutorial building and demonstrations, but they can also simply record the YouTube video as it plays on the screen. If you swipe a cursor across the screen or make any other movements, however, it will also record these because it grabs everything happening on the screen in real time.
App Options
Video recording apps are made specifically for downloading YouTube videos and videos from other programs. Downloading from an Android device is extremely difficult as Google manages the ecosystem and prevents downloads. iOS is easier when attempting to save YouTube videos. You can download to the cloud then save the video on a USB by accessing your cloud on a laptop or home computer with a USB port.