[dba7dba]

I also recommend asciinema.

A tutorial using asciinema in action.

https://asciinema.org/a/188659

You can't add voice into asciinema itself but a asciinema recording URL would be an excellent handout material (like powerpoint) to give to students. Your students can view Terminal action with very clear text, unlike videos where reading text can be difficult.

Even if you use other method for recording/delivering your voice/audio lecture, including Asciinema replay link would be a huge benefit to students.