VG-10 stands for V Gold 10 ("gold" meaning quality), or sometimes V-Kin-10 (V金10号) (kin means "gold" in Japanese), and is a cutlery grade stainless steel produced in Japan. VG-10 is a stainless steel with a high carbon content. Because of how well VG10 holds an edge and its ability to withstand rust, VG10 has became the most popular steel for professional chefs and cooking enthusiasts.
VG 10 stainless steel is also a high carbon steel, even though carbon only makes up a relatively small amount of the total material of the blade. VG 10 stainless steel is a mixture that contains roughly 1% carbon, 1% molybednum, 15% chromium, .2% vanadium and 1.5% cobalt. All of these relatively small amounts of other metals give the VG 10 steel its unusual properties, such as its ability to hold an edge, and the sheer durability of the steel in question. It is one reason why the VG 10 label has been so highly prized among so many people, ranging from chefs to knife collectors.
According to Takefu, the Cobalt makes the substrate stronger, and the addition of Moly and Vanadium form harder carbides increasing the wear resistance and thus improving edge retention. Additionally, VG-10 has excellent corrosion resistance, making it a fantastic all-round steel.