Video   

 
Electronic image capture system.  
Used extensively in film post production. 
The various video formats handle audio in a myriad of ways.
 
In general, analogue systems record audio in two ways:  (1) on linear audio tracks and (2) as part of the video signal. Linear audio tracks are generally poor quality because video tape travels at a relatively slow speed.  (The video head spins.  This allows the tape the high frequency bandwidth necessary for video.) Linear tracks may be recorded independently from the video signal. Audio which is recorded as part of the video signal (often referred to as HiFi - HiFi VHS, Hi8,, etc.) is of a much higher fidelity though must be recorded at the same time as the video signal. Digital video generally has excellent audio potential. 
In addition to the aforementioned format issues, one of the key components to audio quality is the quality of all of the components in the audio chain. Connectors, manual or automatic level adjustments, microphone preamps, metering or lack thereof, all affect the signal quality.
 
 
Format
Format Information
Audio Characteristics
8 mm
Low end home entertainment format
Linear analogue mono audio.  Poor quality.
Hi 8 mm
Medium grade home entertainment format.  Some professional camcorders.
Stereo audio recorded as part of the video signal - reasonable quality though format degrades quickly with replaying.  Professional camcorders have reasonable mic preamps, good connectors, the ability to record line level signals and occasionally sound meters. 
VHS (1/2")
Low end home entertainment format.  Commonly found in video stores, etc.
HiFi VHS uses the video to record audio (better).  Not to be confused with some older "Stereo" VHS units which had two linear audio tracks (bad).  There are usually one (mono) or two (stereo) linear audio tracks which are poor quality due to the slow speed of the tape.  Before the advent of DAT machines low budget studios would use HiFi VHS to master tracks. Some of the higher end machines have meters, and adjustable inputs.
Super VHS (1/2")
Low end semi-professional format.  Not used much any more.  Uses a tape cassette similar to VHS but higher quality.
See HiFi VHS. SUper VHS camcorders generally have good connectors and  microphone preamps, etc.
Professional low end analogue format. Still used in post production.
Various flavours. Older formats have two linear audio tracks as well as one "control track" which may be used to control longitudinal time code (an audio signal) for editing and synchronization.  New formats have improved audio capabilities.
Professional, analogue broadcast standard. Beta, Beta SP
Camcorders have professional quality mic preamps (xlr balanced inputs, phantom power, etc.) and other high end features. Format has digital quality audio capability.
digital
Home entertainment, semi-professional and professional.
A variety of ever-evolving formats. "Low end" digital camcorders may have excellent audio recording and playback potential though it can be hampered by poor connectors (typically stereo mini phone), auto-level adjusting and poor microphone preamps.