A blockchain is an ever-amplifying bulletin of cryptographically linked units of data called blocks. Blockchain is a broadcast, public digital journal used to record data of transactions across many devices, so the associated records can be easily changed after changing all sub-sequential blocks. As a result, blockchain is being applied in various industries. As a result, this review paper discusses how blockchain is used in two industries—IoT and financial applications—that stand to gain the most from it. Additionally, this article explores the separation and security issues raised by it and offers some suggestions on how to solve these issues. In this essay, we have examined a number of similar works that dealt with related topics. Last but not least, we explored the general opinion of blockchain technology to examine how various market segment’s view blockchain the association.