The most commonly used wiring method for residential use is called nonmetallic sheathed cable. Other types of wiring methods are knob and tube, as well as service entrance cable.
DB9 is a connector, not a cable. It is most commonly used for RS-232 serial connections like an external modem.
USB-B to USB-A
about £15 the cheapest
Cat 5E
a. Because most office buildings are not wired with coaxial cable
Cat-3 is the most common and least expensive.
a. Because most office buildings are not wired with coaxial cable
The connection speed, most commonly used for cable home networks, is three megabytes per second. The Internet connection speeds have increased greatly in the past 10 years.
Cat 5E
Cat 5E or Cat5
conduit