At school, college, and workplace, if your domain is computer science, the textbooks and documents may not be enough to teach others effectively. If you want to hand over knowledge to someone, you can share your screen via online software like Teams.
If you're working in IT, the mandatory software you'll use is a screen recorder. If you need to report a systematic error, visual-type content will help your team quickly understand the scenario to provide a fix. You can use the inbuilt version of the screen recorder provided by Windows 10 but in my experience, it is not that user-friendly. It eats much of your hard drive for 10 mins of the screen video.
You might also like to read: 10 Best Skillshare Classes to Improve Your Skills
You might also like to read: 10 Best Skillshare Classes to Improve Your Skills
There are many free screen recorder software available on the Internet which come with limitations. Either it will allow you to record the screen for a limited time per video or puts the company's watermark or both together.
If you run an online business and would like to promote your site or digital product, you'll not like someone's watermark in your video. Instead of directly going for paid software, I would recommend you try a free screen recorder which has no such limitations.