I taught a Linux workshop to blind/visually impaired in Virginia this summer.
orca is the main screen reader used in Linux. Most of them were familiar with Jaws on Windows. Orca offers a kinda similar screen reader experience but the hotkeys are different (ability to re-read a line, jump a word, jump a section, etc)
They were on laptops so I could still look over their shoulder if they needed help, but after a while they all got the hang of it and we were "off to the races". It was thrilling to see it click for them and to see such a completely different user experience.
The short of it is that he uses a screen reader. The thing reads out what is shown on the screen. Things like application title when you alt-tab, page contents on websites, field and button labels/names in forms when you tab through it, etc. I see that u/grendelt already gave some software examples; for mobile I might add that you could try Talkback (built into Android).
