A light-blocking device that falls under the general category of "Grip equipment." Generally used in a studio to prevent illumination from a studio light striking a portion of a scene. A "gobo" can be a simple piece of opaque cardboard or a sophisticated material in a specific shape, often a rectangle or square. "Barn doors" are gobos. The rectangle defined by the GOLDEN MEAN.
in audio terms, a moveable barrier used in the studio to increase isolation, typically between a noisy sound source (i.e., drums or a guitar amp) and other mics or instruments in the studio. Alternatively, gobos can be used to "protect" a low-level source, such as a vocalist's mic, from nearby higher-level sounds.
In video a scenic piece through which the camera shoots and which will become a part of the scene's foreground. For example, by shooting thorough a gobo of a keyhole-shaped piece of black cardboard, the impression is given that the camera is peering through a keyhole.