It depends of the type of service.
Cable providers will bring a coax cable line to your residence and split it to connect a modem/ wireless router for the internet and a cable box for each TV.
Some new cables systems like Altice will bring one cable to the main all-in-one hub, which provides wireless internet, TV and phone services.
Verizon FiOS will bring an optical line to your residence and install an ONT (Optical network terminal) inside or outside. If the unit is placed outside a battery backup will be placed inside. Don't allow them to install it in a bedroom. When the battery needs to be change it will start beeping until reset or the battery is changed.
The will have a wireless router connected to the ONT and like the cable companies, they will use coax to bring service to each cable box connected to a TV.
Whoever you choose make sure to let the tech know where you want holes to be made, placement of the ONT and modem/router.
If you don't tell them, they will run cables and place equipment wherever is easier for them.