What is an ISP?
An Internet Service Provider (ISP) is the industry term for the company that is able to provide you with access to the Internet, typically from a computer. If you hear someone talking about the Internet and they mention their “provider,” they’re usually talking about their ISP.
Your ISP makes the Internet a possibility. In other words, you can have a shiny computer with a built-in modem and could have a router for networking, but without a subscription with an ISP, you won’t have a connection to the Internet.
ISPs make it possible for customers to access the internet while also providing additional services such as email, domain registration and web hosting. ISPs may also provide different internet connection types, such as cable and fiber. Connections can also come in the form of high-speed broadband or non-broadband. The Federal Communications Commission (FCC) states that to be considered high-speed, a connection must have download speeds of at least 25 megabits per second (Mbps) and upload speeds a minimum of 3 Mbps.
How do ISPs work?
ISPs are connected to one or more high-speed internet lines. Larger ISPs have their own high-speed leased lines, so they are less dependent on telecommunications services and can provide better service to their customers.
ISPs also keep thousands of servers in data centers -- the number of servers depends on their internet service area. These large data centers manage all customer traffic. Multiple ISPs are also connected to large backbone routing centers.
ISPs are grouped into the following three tiers:
- Tier 1 ISPs. These ISPs have the most global reach and own enough physical network lines to carry most traffic on their own. They also negotiate with other tier 1 networks to allow free traffic to pass through to other tier 1 providers. Tier 1 ISPs typically sell network access to tier 2 ISPs.
- Tier 2 ISPs. These ISPs have regional or national reach and are service providers that connect tier 1 and tier 3 ISPs. They have to purchase access to larger tier 1 networks, but are peers with other tier 2 ISPs. Tier 2 networks focus on consumer and commercial customers.
- Tier 3 ISPs. These ISPs connect customers to the internet using another ISP's network. Tier 3 ISPs use and pay higher-tier ISPs for access to internet services. They focus on providing internet access to local businesses and consumer markets.
ISPs and the different types of services
ISPs provide the following internet services:
- Cable. This service uses coaxial cable -- the same type of cable that delivers TV. Cable internet has low latency, which is good for users who need less delay or lag time. Cable has a download speed of 10 to 500 Mbps and an upload speed of 5 to 50 Mbps.
- Fiber. Fiber internet uses fiber optic cable to transmit data to provide much faster speeds compared with cable or digital subscriber line (DSL). Fiber has download speeds of 250 to 1,000 Mbps and upload speeds of 250 to 1,000 Mbps. Fiber is good for online gamers and other heavy internet users.
- DSL. DSL connects users to the internet using a telephone line. It is widely available, but is slowly being replaced by more reliable broadband connections such as cable and fiber. DSL is slower and offers download speeds of 5 to 35 Mbps and upload speeds of 1 to 10 Mbps. It is a good option for users in rural areas and those who mainly surf the web or stream TV on only one device.
- Satellite. Satellite internet access works through the use of communication satellites. Ground stations relay internet data as radio waves to and from satellites that are likely in low Earth orbit and to farther ground stations. Satellite is slower, with download speeds of 12 to 100 Mbps and upload speeds of 3 Mbps, but it is a good option for users in remote areas.