The word "Open Source" is everywhere with Linux Technology and GNU foundation. In addition to open source software's and operating systems, Open Source Hardware is also progressing and becoming center point of attraction for researchers across the nook and corner of the world. The most widely adopted Open Source hardware available right now is "Arduino". Arduino has various products like hoards, Lilypad's and shields. The aim of this research paper is to explore the world of Arduino technology in terms of Boards, Lilypad's and Shields covering in depth regarding-Technical Specifications, features and real-world applications. Arduino technology has enabled various manufactures and research enthusiasts to come out with their own customized boards and shields as per their research requirements and area of implementations. Arduino Open Source community is also providing platform for researchers to come up with innovative research applications and market ready products in terms of Home Automation, Robotics, Wireless Connectivity, Drones and many others.