Hi8 is a higher quality version of 8mm. The tapes are the same size and shape as 8mm tapes, and they can be used interchangeably in some cases. The difference is that metal evaporated tape is used, which allows it to record more resolution. It is an analog format. It has around 400 lines of resolution, which is a big improvement over 8mm tapes. Hi8 is the highest quality consumer analog tape available. It is also the only analog format that is still being widely used, although it has been made obsolete by MiniDV and Digital8.