ODD : Acronym for Optical Disk Drive (CD/DVD).
ONVIF : Acronym for Open Network Video Interface Forum. This is a growing standard for IP camera interface.
Operating System : This is the program that controls the basic operations of a computer. Examples are Windows 7, Windows Vista, Windows XP, Linux, Apple, and UNIX.
Optical Zoom : This is the normal zoom capability of a variable focal lens. Example: A 5mm to 50mm zoom lens can be positioned any distance with no loss in video quality. By comparison, digital zoom enlarges the image but reduces the quality.
OSD : Acronym for On Screen Display. OSI model: OSI (Open Systems Interconnection), are the rules for network communication that the TCP/IP protocol carries out.
Over scanning (Over-scan) : This technique is used in consumer display products to extend the deflection of a CRT's electron beam beyond the physical boundaries of the screen to ensure that images will always fill the display area. See also under scanning.