What is an ISP? Understanding Internet Service Providers

Internet service providers are the gateway between you and the global internet, powering homes, offices, and mobile devices alike. In this article, we’ll explain what an ISP is, what ISPs do, how it all works, the different types of ISP connections, and how wireless alternatives - known as WISPs - are changing what internet access looks like today.

What is an internet service provider (ISP)?

An internet service provider (ISP) is a company that gives you access to the internet. ISPs use different technologies - such as cable lines, phone lines, fiber optics, satellites, or cellular networks - to connect your home, business, or mobile device to the wider internet.

When you browse the web or send a message, your request travels through your ISP’s network before reaching the destination server. Without an ISP acting as this intermediary, your device wouldn’t be able to reach the internet at all.

ISPs also manage your connection’s speed, stability, and routing to ensure your traffic gets where it needs to go. Some ISPs specialize in residential service, while others focus on businesses, mobile devices, or rural areas.

What ISPs do

ISPs handle several behind-the-scenes tasks that make your internet connection possible, including:

Providing internet access through cable, DSL, fiber, satellite, or cellular networks.

Assigning IP addresses so your devices can communicate with websites and apps.

Managing network infrastructure like routers, servers, and data routes to keep your connection stable.

Offering additional services such as:
- Website hosting
- Email accounts
- Domain name registration
- Security tools like DNS filtering or parental controls

5 common types of ISP connections

ISPs use different methods to deliver internet service, and availability varies by location and provider. Five common connection types include:

Cable internet: Delivered through coaxial cable lines, and often used for home and small business connections

DSL (Digital Subscriber Line): Uses telephone lines for data transmission and is available in many residential areas

Fiber-optic internet: Uses glass strands to transmit light signals and offers consistent performance where available

Satellite internet: Connects through satellites and a dish installed at the home, and often used in areas without wired infrastructure

Cellular / Wireless internet (WISP): Uses nearby cellular towers and can support homes or locations without traditional wired access

ISP vs. WISP: What’s the difference?

While ISPs primarily use wired technologies, Wireless Internet Service Providers (WISPs) rely only on wireless networks - often cellular - to deliver home or mobile internet. WISP may also be referred to as Fixed Wireless Access (FWA), a term commonly associated with 5G-enabled ISPs.

Category	ISP (Internet Service Provider)	WISP (Wireless Internet Service Provider)
Connection type	Uses wired technologies such as cable, DSL, fiber, or satellite connections.	Uses wireless signals, often through cellular networks like LTE or 5G.
Installation	May involve wired setup or technician visits depending on the service type.	Typically involves wireless equipment that can be set up with minimal installation.
Location use	Designed for use at a fixed home or business address.	Can support fixed locations and may offer flexibility depending on the service.
Equipment	May require a modem, router, or other wired hardware.	Generally uses a gateway that connects wirelessly to nearby towers.
Availability	Dependent on existing wired infrastructure in the area.	Availability varies by tower coverage and wireless network reach.
Environmental factors	Performance can be influenced by physical infrastructure or local wiring.	Performance can be influenced by signal strength, distance from towers, and surrounding terrain.
Use cases	Common for homes or offices with access to wired networks.	Useful in areas where wired options are limited or where flexible installation is preferred.

In summary, ISPs primarily use wired or satellite infrastructure to deliver internet service, while WISPs provide access through wireless signals such as LTE or 5G, offering different setup and availability options depending on location and network type.

Who is my internet service provider? 4 tips to identify your ISP

If you’re unsure who your ISP is - especially if you just moved or someone else set up your internet - there are a few easy ways to check.

Check your router and modem or gateway: Most routers from ISPs have branding or stickers that show the provider’s name.

Look at your internet bill: Your monthly statement or bank transaction description will show the provider.

Use an online lookup tool: You can search “Who is my ISP?” and visit a trusted lookup site. These tools use your public IP address to identify your ISP.

Ask your building management: Apartment complexes often partner with specific ISPs or include internet in rent.

How to fix ISP connection issues: 7 steps

When your internet slows down or stops working, the cause is often something simple. Here are seven steps to troubleshoot before calling your provider.

Restart your router and modem or gateway by unplugging it for 10–15 seconds and plugging it back in to refresh the connection and clear temporary errors.

Check for local service updates or outages through your provider’s website, app, or support channels to see if the issue is happening beyond your home.

Inspect all cables and physical connections to confirm power cords, Ethernet lines, and coax or phone cables are firmly connected and free of damage.

Reduce overall network congestion by pausing large downloads, disconnecting unused devices, or adjusting usage if multiple people are streaming or working online.

Move closer to your Wi-Fi router or reposition it to reduce interference from walls, appliances, or furniture that may weaken the wireless signal.

Review your router’s configuration settings to verify the network name, password, security mode, and firmware version are correct and up to date.

Contact your ISP for additional support if the issue continues so they can check your line, review your account, or help diagnose equipment-related problems.

Security and ISPs

ISPs play a role in how your connection is secured. They manage the network that your traffic moves through, assign IP addresses, and provide DNS services that help route your requests. Some ISPs also offer optional tools such as firewalls, security filters, or parental controls.

For added privacy or customization, many people choose to adjust their router settings or use services like VPNs, depending on their needs.

7 frequently asked questions (FAQs) about ISPs

Is Wi-Fi the same as an ISP?

No. Wi-Fi is a wireless signal inside your home. Your ISP is the company providing your internet connection.

What’s an example of an ISP?

Examples include cable companies, fiber providers, satellite companies, and wireless providers.

Can I switch ISPs?

Yes. Availability depends on your location and the types of networks installed in your area.

What happens if my ISP goes down?

If you're ISP goes down, you will temporarily lose internet service. Outages can be caused by equipment issues, weather, construction damage, or maintenance.

What are the best ISPs for rural areas?

In rural regions, satellite and wireless ISPs are often the most accessible options.

What’s the difference between a modem and an ISP?

A modem is hardware that connects you to your ISP’s network. An ISP is the provider delivering the internet service.

Can a mobile network be used as a home ISP?

Yes. Many WISPs use 4G LTE or 5G to provide home internet access without cables, making them a flexible alternative.

Final thoughts on what an ISP is and how different providers connect you

Understanding what an ISP is helps you see how your devices access the internet through different technologies, whether wired or wireless. Now that you know more about what ISPs are, common connection types, and how ISPs differ from WISPs, you can make more informed decisions about the type of internet service that fits your home or lifestyle.

Interested in exploring wireless options? T-Mobile Home Internet offers several unlimited 5G plans to choose from. Check availability in your area and then try it free for 15 days to see if it works for you.

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