Sprinter is a hybrid rail service operating in the North County area of San Diego County between the cities of Escondido and Oceanside, California, United States. The service uses the 22-mile (35 km) Escondido Subdivision of the San Diego Northern Railroad. Station platforms were constructed for the line's fifteen stations serving the cities of Oceanside, Vista, San Marcos, and Escondido. The line provides service to California State University, San Marcos and Palomar College. Sprinter service operates every 30 minutes and is targeted towards students and commuters.

Light rail is a mode of rail-based transport, usually urban in nature. When compared to heavy rail systems like commuter rail or rapid transit (subway), light rail systems are typically designed to carry fewer passengers and are capable of operating in mixed traffic or on routes that are not entirely grade-separated. Systems typically take one of four forms: the "first-generation" legacy systems, the "second-generation" modern light rail systems, streetcars, and hybrid rail systems. All of the systems use similar technologies, and some systems blur the lines between the different forms.