The world is moving towards autonomous systems and hence all systems need an intelligent feedback control mechanism to achieve their potential for various applications. IoT is one of the leading technologies that can transform the current trends which will shape the future of industry and business in the coming years. As seen since 2017 IoT has converged with Block-chain technology which is used to track and coordinate billions of smart objects, facilitating transparency of transactions and providing better security and privacy by using efficient cryptographic algorithms. Different technologies are utilized to connect the different parts of IoT to the sensors which includes: Ethernet, Bluetooth, Wi-Fi, Wi-Max, Long Term Evolution (LTE) and the latest technology of Li-Fi. Interoperability and standardization of IoT devices and protocols are key challenging issues which deter the end users to select consumables of their choice and choose service providers based on their area and requirements. However, numerous problems and challenges raised by IoT need more attention in order for impending benefits to be comprehended. IoT has the potential to enhance customer relationships and boost the growth of business by improving quality, productivity and reliability while reducing costs, risk and accidents. This paper provides an overview of IoT and its architecture and applications, such as fully automated smart industries, smart cars and home security.