Society of Motion Picture and Television Engineers.
The SMPTE standards have been very important for cinematography and television, especially for professional applications.
Their importance has decreased since the transition to digital video, when many relevant standards have been issued by other organizations, but many SMPTE standards are still important, especially regarding the formats used for distributing digital movies for movie theaters.
Didn't realize they were so broad in scope. The only thing I had heard of was "SMPTE codes" used in audio recording to sync up multiple multi-track recording machines, so that e.g. you could record 30 tracks using two 16-track recorders (with one track on each machine used for the sync). I never bothered to look up what SMPTE meant.
The SMPTE standards have been very important for cinematography and television, especially for professional applications.
Their importance has decreased since the transition to digital video, when many relevant standards have been issued by other organizations, but many SMPTE standards are still important, especially regarding the formats used for distributing digital movies for movie theaters.