Arduino is usually an open source electronics platform accompanied with a hardware and software so that anyone can design, develop and test complex electronics prototypes and products. Besides, the hardware consists of a micro controller with other electronic components which generally can be programmed using the software to do almost any task.
What makes Arduino different from others is the simplicity of the Arduino language that helps to write complex codes easily. Arduino is said to be an excellent designed open source platform where specially designed boards which can be programmed using the Ardunio Programming Language or APL.
Nowadays, the presence of Arduino is not only spreading among hobbyists, but it is also expanding its roots in different sectors and used by experts for making prototypes of commercial products. To know more, read: https://www.engineersgarage.com/articles/arduino
To experience it live, you can join the workshop by registering yourself at: http://www.gosigmaway.com/events/robotics-iot/robotics-embedded-system/44-robosigma-arduino-4-beginners-workshop.html