Reference. SoftwareSerial. Reference Language | Libraries | Comparison | Changes The Arduino hardware has built-in support for serial communication on pins 0 and 1 (which also goes to the computer via the USB connection).
The native serial support happens via a piece of hardware (built into the chip) called a UART. This hardware allows the Atmega chip to receive serial communication even while working on other tasks, as long as there room in the 64 byte serial buffer. The SoftwareSerial library has been developed to allow serial communication on other digital pins of the Arduino, using software to replicate the functionality (hence the name "SoftwareSerial"). How to Build a Robot Tutorial - Society of Robots. What is the UART?
The UART, or Universal Asynchronous Receiver / Transmitter, is a feature of your microcontroller useful for communicating serial data (text, numbers, etc.) to your PC. The device changes incoming parallel information (within the microcontroller/PC) to serial data which can be sent on a communication line. Adding UART functionality is extremely useful for robotics.