Blockchain is the technology which in the last decade has influenced our lifestyles most. Bitcoin is a word used frequently for Blockchain. For example, scalability and protection issues that stands up because of the immoderate numbers of IoT items within the community. The server/client version calls for all devices to be connected and authenticated via the server, which creates a single point of failure. Therefore, shifting the IoT machine into the decentralized course may be the right selection. One of the popular decentralization structures is blockchain. The Blockchain is a powerful technology that decentralizes computation and management methods that may resolve many of IoT troubles, in particular safety.Many Blockchain still confuse Bitcoin, even if it's not equal. Bitcoin is one of several applications are available in Blockchain technology. First of all we present an outline of blockchain architecture and compare a few popular consensus methods in various blockchains. This study also introduced the entire blockchain ecosystem of all the articles we examined and summed up. Furthermore, analyses and consensus models are conducted on many blockchain platforms. Finally, we analyze key issues which are necessary for the future of blockchain technology in these key fields to be broadly available.