The Internet of Things (IoT) and Blockchain are some of the most popular and most significant trends in technology right now. To some extent, one can even say the technologies are a perfect pair as some of the issues like security and trust that come with IoT are taken care of by integrating Blockchain. The decentralized and encrypted nature of Blockchain makes it more robust and tamper-proof than the centralized systems used for IoT. This paper is a literature review that discusses the origins and workings of these technologies as well as discusses the application areas by integrating these two technologies and the challenges faced in integrating these technologies.