Not sure if I used the correct terms but what is the difference in security and privacy between downloading from a public wifi (or a closed wifi; with password) and mobile hotspot (sharing 4G/5G data from your phone to your computer)? Which one is recommended or does it not matter?
Short answer: Mobile hot spot (w/ your own cellular device) is preferable to public wifi from a security perspective.
There are other considerations, such as how much cellular data downloads cost to you, what sites you’re visiting, what you’re actually doing, etc. In general, it’s advisable to avoid public wifi if you can, but if you must connect to public wifi, then you should make darn sure you connect to the right network (watch out for imposter networks w/ a legitimate looking name) and use VPN (ideally a paid service) to encrypt your traffic. Even with both of these measures, you’re best off avoiding sensitive activities like online banking on public wifi. If you must do banking or other sensitive stuff, either do it on your phone or wait until you get home.
Hope this helps.
Editing to add: When I initially responded, I’d forgotten which community I was in. In this context, I believe the other responses are better than mine, but I’ll keep mine up in case it helps other readers.
It depends on his threat model and what he’s trying to hide really. Public WiFi is fine, as long as you validate/check the SSL cert it’s using is from your bank and is legitimate. Using public WiFi with a VPN is more secure as long as you trust your VPN provider. If he’s asking these questions, then he’s probably not doing banking though, and should ideally be using VPN+TOR or something similar.
If the thing they are trying to do requires lots of data transfer, somehow, then TOR would not be ideal. Big Data makes TOR a bad experience. For that use case, a VPN alone is mostly enough (except the risks that can mitigated by reading other comments here)
Yeah absolutely if he’s downloading Linux ISOs, just use a VPN and you’ll be fine 99% of the time. TOR if he is doing anything else surrupticiaous. 😬