<p>DC–DC converters are fundamental building blocks in modern power electronic systems, enabling efficient voltage regulation for applications such as renewable energy integration, electric vehicles, energy storage systems, and portable electronics. This paper presents a structured review of DC–DC converter technologies, covering conventional unidirectional and isolated topologies, bidirectional interfaces, and emerging impedance-source converter families. The review emphasizes recent advancements in resonant and soft-switching architectures, wide-bandgap semiconductor integration, and intelligent digital control strategies. Special attention is given to bidirectional and impedance-source converters due to their importance in high-efficiency and flexible energy systems. Key performance aspects are comparatively analyzed to highlight practical design trade-offs. By consolidating topology classification, performance considerations, and application-oriented insights into a unified framework, this paper provides an up-to-date reference for researchers and engineers developing next-generation DC–DC converter solutions.</p>