Arduino is an open source hardware and software company that designs and manufactures single-board microcontrollers for building devices that can sense and control objects. The Arduino Web Editor allows users to write and upload code directly from a web browser to any Arduino or Genuino board after installing a plugin. It includes main libraries like WiFiLink, ArduinoCloud, and GSM to enable WiFi, cloud, and cellular connectivity in projects. The Robot library interfaces with sensors and peripherals on robot control boards and includes examples like line following, remote control, and picture browsing.