Witeboard is a collaborative online whiteboard. To use it just head to the site and start drawing. Witeboard has some basic drawing tools and text tools. To share your Witeboard whiteboard all you have to do is give someone the URL that's assigned to it and they can start drawing on it.
It is possible to create an account on Witeboard but you don't need to create one. The benefit of creating an account is that you can save your work and access it from multiple devices.
In the following video I demonstrate how to use Witeboard.
Applications for Education
There are a lot of whiteboard tools on the market today. I use Google's Jamboard almost daily in my classroom. If Jamboard's not your jam, Witeboard is a nice alternative to try.
Like all collaborative whiteboard tools, Witeboard could be handy to use when you need to sketch a concept for students during a virtual meeting (I made one today to explain port forwarding). It's also a handy tool for students to use to show you their sketches of a concept.