I have question about mobile visitors. What information can a website administrator get from mobile user?
For example: when I visit www.site.com from my phone device (I use mobile internet, not WiFi) what they will know about me? Can they can get my mobile number, imei code, or mobile device information?
This is kind of a broad question, but I will try to explain briefly the general concept. First of all it's fundamental to understand what a connection is, and what a protocol is. A protocol, briefly said, is a way the two objects communicate in. I would recommend you to watch this playlist.
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Now about the connection. The connection by itself involves all the path from you/your device to the server you need to communicate with, and thus, summarising these two, we can make a basic conclusion. The server can gets your IP address, which is due to the connection concept, and also info about what program exactly do you use, because of the protocol. The protocol may require your program to send lot's of information from it, but if we are talking about web browsers, they do not share the users private information for privacy and security reasons. That's it, I hope I could help you somehow.