ISPs (Internet Service Providers)

What is an ISP?

An Internet Service Provider (ISP) is a company that delivers Internet access to homes, businesses, and other organizations. ISPs use a range of technologies—cable, DSL, fiber-optic, satellite, and wireless—to connect customers and often bundle additional services such as email, web hosting, domain registration, streaming or TV packages, and security or cloud services.

How ISPs connect you

Early public Internet access relied on dial-up connections over phone lines. As demand and technology progressed, broadband options (cable modems, DSL, and fiber) replaced dial-up, providing much higher speeds and always-on connectivity. ISPs manage the flow of data between end users and the wider Internet, routing traffic across a layered network of providers.

ISPs typically interconnect with one another. Smaller, local ISPs buy upstream access from larger providers; those larger providers in turn link to even bigger networks, leading to a hierarchy that culminates with Tier 1 carriers—networks that can reach the global Internet without paying for transit.

Tier 1 ISPs and infrastructure

Tier 1 ISPs own or control extensive backbone infrastructure—fiber-optic cables, long-haul networks, and major peering points. Building and maintaining this infrastructure requires massive capital, which helps explain why high-speed access markets can appear oligopolistic or dominated by a few regional players.

New technologies aim to diversify access methods. For example:
* Low-Earth-orbit satellite constellations (e.g., Starlink) deliver broadband without relying on ground fiber.
* Mobile network advances such as 5G are expanding high-speed wireless broadband options.
* Select companies (e.g., Google Fiber) have experimented with deploying fiber directly to neighborhoods, with availability limited to select markets.

Common ISP technologies

• Fiber-optic: Highest capacity and speeds; requires new fiber deployment to homes or neighborhoods.
• Cable: Shared neighborhood bandwidth delivered over coaxial lines; speeds can vary with local demand.
• DSL: Internet over existing telephone lines; widely available but typically slower than cable or fiber.
• Satellite: Useful in remote areas; latency and data caps can be limiting factors.
• Fixed wireless and mobile (4G/5G): Wireless links that can provide broadband where wired infrastructure is impractical.
• Dial-up: Legacy option still used in some very remote locations.

ISP vs. Wi‑Fi

An ISP provides the Internet connection to a location. Wi‑Fi is a local wireless technology that distributes that connection within a home or business. A modem (or gateway) connects to the ISP; a router then creates a Wi‑Fi network so devices can access the modem’s Internet link wirelessly.

Major examples and services

Large telecommunications companies commonly operate as ISPs while also offering phone, TV, cloud, and managed-network services. Examples of widely known U.S. ISPs include Comcast, Charter, AT&T, and Verizon. These companies vary by geography and by which technologies they deploy (cable, fiber, DSL, wireless).

ISPs often sell bundled packages—Internet with TV and phone—or business services such as data center access, managed Wi‑Fi, and security solutions.

Assistance programs

Government and nonprofit programs exist to help low-income households afford broadband. One example provides discounts on monthly service and device costs for eligible families. Availability and eligibility vary by country and program.

Choosing an ISP

When comparing providers, consider:
* Available technologies in your area (fiber, cable, DSL, satellite, fixed wireless)
* Advertised download and upload speeds and typical real-world performance
* Data caps, latency, and reliability
* Bundles, add‑on services, and contract terms
* Customer support reputation and local availability
* Price and any promotional or long-term costs

Bottom line

ISPs are the gateways that deliver Internet access using a variety of underlying technologies. Market structure and infrastructure costs mean availability and performance differ widely by location. Advances in satellite broadband and wireless technologies are expanding options, but fiber and established cable networks remain central to high-speed Internet delivery. Choosing the right ISP depends on local availability, speed needs, budget, and desired services.