I’m studying C++ and I looked at C, it’s a really strong programming language.

Wow! This is so cool, I’m learning C++ myself :)

What happens when you insert a SIM card? The operator receives: The IMEI of your phone. The SIM card number (ICCID). The Wi-Fi network name (if Wi-Fi Calling is enabled). The location (by towers). And yes, this permanently binds the IMEI to the SIM card in their database, especially in countries that require SIM registration. If the SIM card is registered to you, then: Any insertion into the device is logged. IMEI + number = you can track which device is being used and by whom. Banking Apps usually check: The presence of a SIM card. Sometimes - so that the SIM number matches the number specified in the banking system. The presence of active Internet (mobile or Wi-Fi). Something like that