Credit Card Numbers - Visa. These Credit card numbers validate for Visa credit cards. The number and information is as real as it can be, and contains valid bin information. The structure of the credit card number starts with a valid bin number and also validates against the LUHN's formula.
UART is a protocol (Universal asynchronous receiver/transmitter ) for serial transfer of information. You ask about an embedded system with mentioning which so I'll assume that you have a block diagram with one indicating UART.
This popup is called User Account Control and in short UAC and reminds you to re-check the application you are installing or running whether it is secure for your PC. In this way, it works for boosting security consequences of your PC. But sometimes it annoys you. It is also present in your Windows 10.