Cat6 Ethernet Cable

Anyone can tell me where to buy Cat6 or Category 6 Ethernet cables? I have to buy the Ethernet cables before the technician come to set up the networking for us. He request boss to get ready the Ethernet cable because he has many technical work to do recently and might not able to buy for us. Boss order me to buy the cable but I do not know what cable is that! I am totally do not know how and where I find it. :(