> For the complete documentation index, see [llms.txt](https://longer-vision-robot.gitbook.io/arduino-full-stack/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://longer-vision-robot.gitbook.io/arduino-full-stack/02_programming_grammar/07_communication_classes.md).

# 2.7 Communication Classes

## 2.7.1 Enumeration of Arduino Communication Classes

Several Arduino communication classes are enumerated as follows:

* [Arduino Stream](https://www.arduino.cc/en/Reference/Stream)
* [Arduino Serial](https://www.arduino.cc/en/Reference/Serial)
* [Arduino Wire](https://www.arduino.cc/en/Reference/Wire)
* [Arduino SD](https://www.arduino.cc/en/Reference/SD)
* [Arduino Ethernet](https://www.arduino.cc/en/Reference/Ethernet)

## 2.7.2 void Serial.print(val, format) and void Serial.println(val, format)

* **brief**: print data to the serial port, without/with carriage.
* **param**:
  * **val**: the value to print.
  * **format**: data format while printing.
* **return**: void.