ISP stands for internet service provider, the company you pay to connect your home, phone or business to the internet. The router on your shelf links your devices to each other, but the ISP is what links that router to the rest of the world, through a cable, a phone line, a fiber line, a radio signal or a satellite dish.
When your connection drops and every site fails to load, the ISP is usually the first call. It is also the company whose name appears on your monthly internet bill, which may be bundled with TV or phone service.
Quick facts
Stands for
Internet service providerType
Initialism, said I S PWhat it does
Connects customers to the internet and assigns them an IP addressConnection types
Cable, fiber, DSL, fixed wireless, cellular, satellitePlural
ISPsOther meanings
Individual service plan, independent study program, state policeNot to be confused with
Your router or your Wi-Fi network
What ISP stands for and what an ISP does
Each word tells part of the story. Internet is the global network of networks. Service is what you pay for each month. Provider is the business that delivers it. In practice, an ISP handles several jobs:
- Runs the physical line or signal that reaches your building.
- Gives your connection an IP address so other computers can send data back to you.
- Often supplies DNS service, which turns web addresses into IP numbers.
- Sells plans by speed, measured in Mbps or gigabits per second.
- May rent you a modem or a combined modem and router.
Types of internet service
| Type | How it works | Typical notes |
|---|---|---|
| Fiber | Light pulses through glass strands | Very fast both ways, where available |
| Cable | Shares the coaxial lines used for cable TV | Fast downloads, slower uploads |
| DSL | Runs over copper phone lines | Speed drops with distance from the hub |
| Fixed wireless | Radio link from a tower to an antenna on the home | Common in rural areas |
| Cellular home internet | Uses a mobile network, such as LTE or newer | Easy setup, speed varies by signal |
| Satellite | A dish talks to satellites in orbit | Reaches remote places |
Which types you can choose from depends on your address. Many homes have only one or two options.
ISP vs router vs Wi-Fi
People often blame the wrong thing when the internet is slow. Here is how the pieces fit together.
- The ISP brings the connection to the edge of your home.
- The modem turns the ISP's signal into data your network can use.
- The router shares that connection among your devices.
- Wi-Fi is the wireless link from the router to phones and laptops. A wired link uses an Ethernet cable on your LAN.
A help desk call: "Your laptop shows full Wi-Fi bars but no internet." The agent explains that the Wi-Fi between the laptop and router is fine; the problem is between the router and the ISP. Restarting the modem or checking for an outage in the area is the next step.
What your ISP can and cannot see
Because all your traffic passes through the ISP, it can see which sites and services you connect to, though not the contents of encrypted pages (those whose address starts with https). A VPN wraps your traffic in another layer of encryption so the ISP sees only that you are connected to the VPN. ISPs also follow laws on data, copyright notices and court orders, and their privacy policies explain what they keep and for how long. Reading that policy is the best way to know your own provider's practices.
Other things ISP can stand for
| Field | Stands for | Example |
|---|---|---|
| Disability services | Individual service plan | A written plan of supports for an adult with a disability |
| Schools | Independent study program | A student works from home under a teacher's guidance |
| Law enforcement | State police, as in Illinois State Police or Indiana State Police | A trooper's patrol car |
| Retail | In-store pickup | An online order collected at the counter |
A school ISP is different from an IEP, the plan for special education services.
Saying and writing ISP
ISP is an initialism. Say it "I S P," one letter at a time. In print it is all capitals with no dots between letters, and "an" comes first because the letter name I opens with a vowel: "an ISP outage." The plural is ISPs, with no apostrophe. For related terms, browse the tech acronyms list.
- "Our ISP is upgrading the lines on our street."
- "Call the ISP and ask whether there is an outage."
- "Rural towns often have fewer ISPs to choose from."
Questions people ask
What does ISP stand for?
For most people it means internet service provider, the company that connects you to the internet. In other settings it can mean individual service plan, independent study program or a state police agency.
Is my ISP the same as my Wi-Fi?
No. Your ISP delivers the internet connection to your home. Wi-Fi is the wireless network your router creates to share that connection with your devices.
How do I find out who my ISP is?
Check your internet bill or the label on your modem. You can also look up your public IP address, which usually shows the provider's name.
Can I change my ISP?
Yes, if another provider serves your address. You would cancel the old service, return any rented equipment and set up the new connection.
What is the difference between an ISP and a VPN?
An ISP connects you to the internet. A VPN runs on top of that connection and encrypts your traffic so the ISP and local networks cannot easily see where it goes.