A prime lens is a lens with a fixed focal length as opposed to a zoom lens which has an adjustable focal length. They typically take higher quality photos.
The Sony A7 has a full frame 35mm sensor, interchangeable lenses, amazing low-light sensitivity, RAW capabilities, and can capture professional video.
Universal Tripod Mount
The universal tripod mount is a standard sized threaded adapter that makes every film and still camera compatible with every tripod. Photographers got it right!
Walk Around Lens
In photography a walk around lens is a decent lens for a variety of subjects and situations. Typically it is a zoom lens with an adjustable focal length.