This chapter introduces superconducting memory technologies tailored for cryogenic applications. While conventional non-superconducting memories offer high scalability, they become inefficient under the strict power constraints of cryogenic environments. Superconducting devices, on the other hand, excel by operating at ultra-high speeds with minimal energy dissipation, making them ideal for these settings. This chapter first discusses the need of a superconducting memory in various promising applications. Implementing superconducting memory can address significant challenges in developing large-scale quantum computers, high-performance computing systems, and space exploration technologies by mitigating the limitations of room-temperature memories. Key technologies explored include Josephson Junctions, Superconducting Quantum Interference Devices (SQUIDs), Magnetic Josephson Junctions, Superconducting Memristors, and Ferroelectric SQUIDs. This chapter provides a comprehensive overview of these technologies, setting the stage for the detailed discussions in subsequent chapters.