Each large network that joins the internet is a set of routers run under one technical administration; these networks choose to connect to one another, and no single network is the whole internet.
The Internet Engineering Task Force, founded in 1986, is the main group that writes standards for the internet. Nobody has to join anything to help write them. The IETF has no membership: anyone can take part through a working group mailing list or a meeting, and participants are volunteers who act as individuals. Internet standards are written by teams of engineers in open processes, and the finished standards are published openly and for free; it is up to network operators and software writers whether to use a newly published standard.
A few technical things, such as domain names and IP addresses, must mean the same everywhere, so one group coordinates them: ICANN. ICANN was formed in 1998; it does not control what is on the internet and cannot stop spam. The Internet Assigned Numbers Authority keeps public lists, called registries, of identifiers such as domain names and IP addresses so they are assigned without clashing, and it provides its services without charge.
In 1945, Vannevar Bush described a device called a Memex that could follow links between documents, an early idea behind hypertext; between 1962 and 1963, J. C. R. Licklider wrote memos that imagined an "Intergalactic Computer Network" where anyone could quickly reach information on any subject.
In 1980 the National Science Foundation backed CSNET, which used TCP/IP, and so became an early supporter of the internet. The National Science Foundation launched NSFNET in 1986, and it grew from about 2,000 connected computers in 1986 to more than 2 million by 1993. The NSFNET backbone was shut down in 1995 because commercial internet services had grown quickly.
Internet exchange points are generally considered the successors of four Network Access Points that were set up when the NSFNET backbone was shut down; by May 2013, researchers counted more than 300 exchange points working around the world. Swapping traffic at an exchange point means an ISP sends less of its traffic through upstream transit providers, which lowers the cost of carrying each bit.
A root name server sits at the top of the DNS hierarchy, and it does not hold every website's address; it answers for the root zone and refers the question to the name server for the right top-level domain, such as the one for .com, and referring a question to a server closer to the answer is how DNS avoids one giant list.
To save time, a recursive resolver remembers recent DNS answers for a set period called the time-to-live, or TTL. If someone asks the same question again before time runs out, the resolver can answer from memory instead of asking the root, the top-level domain and the authoritative servers again.
Every IPv6 packet carries a hop limit, a number that each router lowers by one as it passes the packet on. If the number reaches zero, the packet is thrown away; this keeps stray packets from circling the network forever instead of arriving, because a packet that has hopped too many times is simply dropped.
As of November 2026, satellites are useful for reaching places that fiber cables do not yet reach, but cables carry far more data at a much lower cost. ITU's 2025 report found that satellite internet subscriptions were still rare, fewer than one per 1,000 people worldwide. Large technology companies now help pay for new undersea cables, according to ITU and TeleGeography in 2026.
Few ships can repair undersea cables, so a repair can wait for one to become free; in early 2025 an expert said that about 60 to 70 ships worldwide could in theory do repairs, but most are cable layers, and only around 25 to 30 are special ships for repair and maintenance. Cable owners often pay a yearly fee to share repair ships.
As of November 2026, almost all the data that travels between countries goes through cables laid on the sea floor.
Counts of internet users are estimates that get revised: ITU's first 2024 estimate of 5.5 billion people online was later revised to 5.8 billion; in 2025, about 6 billion people, about three-quarters of the world, were using the internet, and about 2.2 billion were not, according to ITU.
The internet is decentralized by design: it is a network of voluntarily interconnected networks, and no organization can force all of them to adopt a new standard.
Words to know
- decentralized: not centrally run
- hypertext: linked text
- registries: public lists
- hierarchy: ranked levels
- backbone: main network
