Google is your friend. Please do a search on google first, thank you.
Mini DV = type of memory which the camcorder records to. Other forms of memory are like DVD, SD cards, hard drive.
HDV = High Definition Video. Type of format which your camcorder records in. Only for recording to HD Mini DV cameras only (e.g. Canon HV20)
Full HD = 1920 x 1080 resolution. Also referred to as 1080i or 1080p (go google)
What is the difference between all three? Simple. You are comparing 3 totally different things altogether.
Please go read up more.
