UART stands for Universal Asynchronous Receiver Transmitter, and what is used on something like the Arduino Uno for programming and various interface tasks, correct?
Arduino has on-chip USART or UART which is used to communicate data serially. Using USART, we can communicate with PC/laptop or serial devices like GSM, GPS, etc.
A universal synchronous and asynchronous receiver-transmitter (USART, programmable communications interface or PCI) is a type of a serial interface device that can be programmed to communicate asynchronously or synchronously. See universal asynchronous receiver-transmitter (UART) for a discussion of the asynchronous capabilities of these devices.