They say mentioning other sites is not good but as long as we focus on functionality it's fine, so lets give this a try...
https://lichess.org/ has takebacks and by default you can draw arrows and highlight squares by right clicking.
With www.chess.com there are no takebacks as far as I know. You can draw arrows and highlight squares, but you have to go into options and toggle it on to do so.
AFAIK the relative levels of popularity among the top 3 have been pretty consistent for at least 5 years.
...With www.chess.com there are no takebacks as far as I know. You can draw arrows and highlight squares, but you have to go into options and toggle it on to do so.
Actually, chess.com does offer takebacks: naturally only available in unrated games. You can select this setting when setting up a daily challenge (might have takebacks for live chess too, but I honestly never checked).
If you pay for membership, then you can also create an analysis board to invite your friend. In there, you can chat, analyze, takeback moves and even create long variations. In this mode, both you and your friend(s) [invited into the analysis board with you] can all make moves on the chess board, chat and so on. Unfortunately, analysis boards can only be created in this way with paying memberships (but even a free, default, membership can still be "invited").
If you use chess.com for this (I do with some friends), then I'd either recommend setting up a "daily" (time control) game and treat it like a live one (but you'll have to re-enter the game after each move). Alternatively, you could set up a live game with a long time control in "custom" if you both are online at the same time for a single sitting.
Teach using Chess.com...
https://www.chess.com/article/view/how-can-i-teach-using-chess-com
Beginners Chess Courses, Lessons, Instructional Resources...
https://www.chess.com/blog/RussBell/beginners-chess-course-instructional-resources
You can also use the in game chat function while playing to give hints or warnings during the game. That would probably be helpful.
I'd like to teach chess to a friend who has never played before. This friend lives in another city, so I'd like to teach them online.
Is chess.com a good site to use for that purpose? Is there a mode where we can freely make moves and take the moves back in order to demonstrate? Any responses are appreciated!