Decentralized Quantum Networks (DQNs) is a rapidly advancing field in the context of quantum computing where decentralized approach is taken for quantum communication and quantum computation without the need for centralized control. By leveraging fundamental quantum principles like entanglement, super-position and quantum memory, DQNs enable secure, scalable and distributed quantum information exchange. This chapter deals with various important quantum gates and their matrix representations and then focuses on the architecture, advantages and challenges of DQNs. The chapter then deals with quantum repeaters and quantum memory as these are central to DQNs. The chapter concludes with the set of real-world practical applications of DQNs and then states the practical constraints that have to be dealt with in-order to deploy fully scalable DQNs. To make DQNs more useful, future work must concentrate on improving error correction, creating reliable quantum memory solutions, and fusing classical networking protocols with quantum networks.