Examples of ISPs, or Internet service providers, include Comcast, Time Warner, Verizon, Charter and Cox. These companies provide individuals, businesses and organizations with Internet access. Many of these ISPs also provide cable television and phone service.
Internet service providers most commonly offer Internet access to individuals through three methods: dial-up, DSL or cable. Dial-up Internet connects users to their ISP through telephone lines. Through this method, a user dials their ISP's telephone number with their modem and cannot make any other calls using that phone line once the Internet is connected. Dial-up is the slowest and least convenient Internet connection method available.
With DSL, which is short for Digital Subscriber Line, users connect to the ISP through a telephone line, and they can make calls on that line simultaneously. DSL is significantly faster than dial-up. A cable connection allows users to connect to their ISP through cable lines, which are the same lines used for cable television. This method is generally the fastest that is available to the average consumer.
ISPs attempt to attract customers by advertising their maximum theoretical download and upload speeds, which are usually measured in megabits or kilobits per second. In practice, download and upload speeds are usually much slower than these theoretical maximums, but they give the user a way to compare ISPs.