You can connect a laptop to a cable modem using an Ethernet or USB cable, depending on the type of ports the laptop and modem have. Alternatively, connect to the modem wirelessly by using a router.
Establish a wired connection by plugging one end of an Ethernet or USB cable into the appropriate port on the laptop. Plug the other end into the modem's USB or Ethernet port.
For a wireless connection, you must purchase a router. Connect it to the cable modem using an Ethernet cable. A WiFi-enabled laptop should find the network automatically. If the laptop isn't WiFi-enabled, purchase and install a wireless network card to give the laptop WiFi capability.