It's my understanding that HDR10 is basically DCI_P3 colorspace with 10 bits per pixel and 4000 nits brightness, while Dolby Vision is 12 bits with a REC2020 colorspace and 10000 nits brightness. No TV's actually support all of that though. The standard is the same as your PC with the ancient sRGB colorspace (for digital TVs .. analog TV used NTSC) and 8 bits per sub-pixel (24 bit color) .. not sure about brightness.
NO TVs actually support all that. Instead, they are rated by how-close they come. For reference, a "nit" is 1 candle per square meter. Imagine 10000 candles in a square meter and you can imagine how bright that TV would have to be! The colorspace is basically the range of colors that the bits are digitizing, and different color spaces are used for different uses.
The colorspace or "gamut" is the overall range of colors. It defines if pure red is blue tinted or orangey, if your white is brilliant white, soft white, or an eggshell, etc. More about color space "gamuts" here ...
http://www.tftcentral.co.uk/articles/pointers_gamut.htm
See TVs compared as to how well they support these standards, here ...
https://www.rtings.com/tv/tests/picture-quality/wide-color-gamut-rec-709-dci-p3-rec-2020
FYI, my Vizio is cheap and says it supports Dolby Vision, but the color is only 10bits. It just rounds or truncates the extra bits to the nearest 10 bit value. It can interpret the Dolby Vision stream, but that doesn't mean it can do everything the standard says it can do. Keep in mind that no TVs will support everything they claim to support. Its a careful marketing strategy to make you think you are getting more than you are paying for. That said, the Dolby still looks better than the HDR10 for the same movie and the Vizio is 1/3 the price of the high-end Samsungs that support a fuller range of the given HDR color spectrums ... but ... an extra 7% for $1000? I'll keep my money. Watch the comparison charts, but also read all the reviews you can.