The classification of modems and wireless routers is not clear. What kind of defined classification do you want? Different definitions have different classifications. The difference between the two is that the modem should be connected with a small head like a telephone line. A wireless router needs a large head of network cable. If your home is connected by telephone line, install a modem first, and then connect a wireless router, so that you can surf the Internet wirelessly. If it is a direct network cable, you don't need a modem. Connect it directly to the wireless router. These things can be bought in the electronic city on the south side of the lake, and other general computer stores also have things.