SVHS

SVHS stands for SuperVHS and was developed by JVC to offer better video quality than the VHS format. 
   
SVHS can offer over 400 lines of horizontal resolution compared to appx. 250 lines of VHS (and compared to appx. 500 horizontal lines of regular TV broadcast). 
   
SVHS uses identical-looking cassettes to those of VHS, but you can recognize the SVHS cassettes by a small hole in the cassette container that VHS cassettes don't have. Basically it is possible to simply punch a hole to VHS cassette to record SVHS material to it, but because VHS cassettes were developed for VHS VCRs, they normally only have enough particles on the tape to hold max 250 lines of horizontal resolution, thus making the SVHS recording onto them useless. 
   
SVHS and VHS use the same colour modulation frequencies and bandwidths, so colour information is always correct. This is an interesting fact, because it means that SVHS does not improve on the colour resolution of VHS, except to reduce possible interference between chrominance in luminance. It should be noted however, while colour information is preserved, chrominance alone cannot generate a useful picture. 
   
Despite this, SVHS recording can't be played back correctly with VHS videos, unless VHS VCR has something called "super quality playback" that allows playing SVHS tapes, but not recording onto them