The standard by which nearly all automobiles / trucks are valued. It’s the bible for anyone (particularly dealers) who wish to buy or sell their rigs.
You can google Kelley's Blue Book and enter your car's info to find out what it is worth if you are thinking of selling it, or what a car you are looking to buy is worth.
As others have said, it is an industry standard book that is blue in color (and now it's also a website) where you can find the market value of your vehicle. They ask several questions to give you an accurate value: mileage, the options it has, overall condition, etc. The joke is that now they ask how much petrol is in it, because these days the amount of gas is a significant contributor of cash value.
Thank you all (. ❛ ᴗ ❛.) I googled Kelley blue book, I don't think we have them in the UK, but at least I know what they are now.
I worked as a programmer for Cars Of Particular Interest. I had to learn C from scratch. Using my data analysis programs they were able to increase the size of the price guide fourfold, changing from a collector car guide to more of a mainstream guide. They sold out to Blackbook - another bigger price guide for over a million dollars. Needless to say I never saw any of that money.