Looking like a small chef's knife, the Santoku (san-to-koo) is a Japanese knife used for chopping vegetables and meats. It's possible it might become your new favourite knife.
The word Santoku roughly translates to "three uses" which is meant to relate to its three main uses, slicing, dicing and mincing.
The blade has a mostly flat profile until you get towards the tip where it curves up. The curve helps to seat the blade on the board when chopping and the flat part of the blade helps get a good clean cut all the way through the vegetable, this makes it great for chopping.
You don't use it with a rocking action that you might be used to with a chef's knife. Instead it's more of a chopping/slicing motion.
Thanks to the sharpness of our knives this knife just falls through food. It's telling just how popular this style of knife is becoming when the Western knife makers have added Santokus to their ranges. If you had to have just one knife then this would be it.