Switching to Comcast need clarification

Solution
Each of them use a different kind of modem; There are DSL modems and also Cable modems.

You don't need to buy a different router. Usually though, the dsl and cable companies have devices that have both the modem, router, and wireless access point built-into the same device. If that is the case, you would have to either remove your existing router, or if your existing router is also a wireless access point, turn off the routing funtion in it via the web admin browser page, and use it as a wireless access point. Usually you won't have a need to do that, unless your house is wired.
Each of them use a different kind of modem; There are DSL modems and also Cable modems.

You don't need to buy a different router. Usually though, the dsl and cable companies have devices that have both the modem, router, and wireless access point built-into the same device. If that is the case, you would have to either remove your existing router, or if your existing router is also a wireless access point, turn off the routing funtion in it via the web admin browser page, and use it as a wireless access point. Usually you won't have a need to do that, unless your house is wired.
 
Solution