SSR2

SSR2 is an acronym used in multiple technical domains, and its precise meaning depends on context. In electronics and electrical engineering, SSR stands for solid-state relay. An SSR-2 label may denote a two-channel device or a specific model within a family of solid-state relays designed to switch electrical loads without moving parts. Such devices use optically isolated inputs to drive semiconductor switches, providing fast switching, quiet operation, and long lifetimes compared with mechanical relays. Common applications include automation, motor control, and power switching where galvanic isolation is desirable.

In software development, SSR2 is sometimes used informally to refer to a second generation of server-side rendering techniques. There is no universal standard named SSR2, but projects may advertise 'SSR2' features to indicate enhancements such as streaming rendering, progressive hydration, or integrated data-fetching pipelines. The concept is platform- and project-specific rather than a formal specification.

In aviation and transportation contexts, SSR is the abbreviation for secondary surveillance radar, which interrogates transponders on aircraft for identification and altitude reporting. Some documentation may refer to 'SSR‑2' to denote a second-generation radar subsystem or a particular configuration within a radar network; however, the exact meaning is deployment-specific and varies by airline, air traffic organization, and equipment vendor.