ISP
Internet Service Provider. A company that sells internet access to homes and businesses.
What ISP means
ISP stands for Internet Service Provider. An ISP is a company that gives you access to the internet in exchange for a monthly fee. Without an ISP, your devices have no way to connect to the global internet, no matter how good your router or modem is.
ISPs come in several forms. Large national carriers like AT&T, Comcast, and Verizon serve millions of customers across many states. Regional providers serve specific cities or rural areas. Some municipalities operate their own ISPs as a public utility. Mobile carriers like T-Mobile and Verizon also act as ISPs for mobile data and home wireless internet.
Your ISP controls the connection from your home to the broader internet. They maintain the infrastructure, assign your IP address, and route your traffic to its destination. They also set the terms of your service, including speed, bandwidth, data caps, and acceptable use policies.
Why your ISP matters for your connection
Not all ISPs are equal. Some prioritize network investment and offer consistently fast speeds. Others oversell their capacity, leading to slow speeds during peak evening hours. The infrastructure type your ISP uses, whether DSL, cable, or fiber, also determines the ceiling on your speeds and the reliability of your connection.
Your ISP also determines whether your area has access to broadband at all. In parts of the country with only one or two providers, competition is limited and pricing tends to be higher. Comparing ISP options before signing a contract can save you money and frustration.
ISP types at a glance
| ISP Type | Technology Used | Typical Coverage |
|---|---|---|
| Cable ISP | Coaxial cable (DOCSIS) | Urban and suburban |
| Fiber ISP | Fiber-optic | Growing, urban focus |
| DSL ISP | Copper telephone lines | Widespread |
| Fixed wireless ISP | Radio towers | Rural and suburban |
| Satellite ISP | Satellite orbit | Nearly universal |
Common questions about ISPs
You can check the FCC broadband map at broadbandmap.fcc.gov, or search individual ISP websites. Entering your address will show which providers and technologies are available at your location.
Yes. This is called throttling. ISPs may throttle speeds after you exceed a data cap or during peak hours. Some ISPs have historically throttled specific services like streaming video. Net neutrality rules, when in effect, restricted this practice.
Yes, significantly. Your ISP's network capacity, congestion levels, and the quality of the infrastructure between your home and the internet backbone all affect your speed test results. Tests run at different times of day can show very different speeds on the same plan.
Related terms
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