Internet

The Internet is a worldwide system of interconnected computer networks that communicate using a common set of rules called protocols. It lets devices of many kinds — from servers in data centres to phones in pockets — exchange information almost anywhere on Earth. The Internet is the underlying infrastructure; services such as the web, email, and video streaming run on top of it.

Its defining feature is decentralisation: no single company or government owns the whole network. Instead, many independent networks voluntarily connect and agree to route each other's traffic.

Origins

The Internet grew out of research in the 1960s and 1970s, much of it funded by government defence and science agencies in the United States. Early experiments linked a handful of university and research computers, testing the idea of packet switching — breaking data into small pieces that travel independently and are reassembled at the destination. This approach was more robust and efficient than keeping a dedicated line open for each conversation.

Key milestones included the development of the TCP/IP protocols, which gave diverse networks a common language, and the decision to open the network to commercial and public use in the late 1980s and 1990s. Growth then accelerated rapidly.

How it works

Data is divided into packets, each carrying addressing information. Routers — specialised computers spread across the network — read those addresses and forward packets hop by hop toward their destination, where they are reassembled. Because packets can take different paths, the network can route around congestion or failures.

Every device on the Internet has an address, historically an IP address. The Domain Name System (DNS) translates human-friendly names into these addresses, acting like a phone book for the network. Protocols define how information is formatted and exchanged; TCP/IP is the foundational pair. Higher-level protocols handle specific tasks, such as fetching web pages or sending mail.

Access and infrastructure

People reach the Internet through Internet service providers, which connect homes and businesses. Backbone networks and undersea cables carry vast volumes of traffic between regions and continents. Data centres host the servers that store and serve content. Wireless technologies, including mobile networks and Wi-Fi, extend access to places without wired connections.

Services built on the Internet

The best-known service is the World Wide Web, which links documents and applications through browsers. Email, messaging, voice and video calls, file transfer, streaming media, online games, and cloud computing all rely on the Internet. Application programming interfaces let different services talk to one another, forming the basis of modern software.

Impact on society

The Internet has reshaped communication, commerce, education, and entertainment. It enables instant global collaboration, gives small businesses access to worldwide markets, and puts vast libraries of knowledge within reach. It has changed how news spreads, how people organise, and how work is done.

But it also brings challenges. Misinformation can travel quickly, and the same reach that empowers can be used for fraud, harassment, or surveillance. Concerns about privacy, security, and the concentration of power in a few large platforms are widely debated. A digital divide persists between those with reliable access and those without.

Governance

Because the Internet spans borders, its governance involves a mix of technical standards bodies, national laws, and international cooperation. Organisations coordinate protocols and addresses, while individual countries set rules within their territory. Balancing openness and innovation with security, privacy, and public safety is an ongoing tension.

Security and encryption

Because data travels across many shared networks, security is essential. Encryption scrambles traffic so that only the intended recipient can read it, protecting password logins, banking, and private messages. Secure versions of common protocols, such as HTTPS for web pages, are now standard. Other defences include firewalls, authentication that confirms a user's identity, and software updates that close known flaws. Attacks such as malware, phishing, and denial-of-service aim to steal data or disrupt services, so security is an ongoing contest rather than a one-time fix.

Mobile and connected devices

Smartphones brought the Internet to billions of people, especially where wired connections were scarce. Mobile networks and Wi-Fi let users connect almost anywhere, and the falling cost of devices widened access. A growing number of everyday objects — thermostats, cars, sensors, and appliances — now connect to the network too, forming the so-called Internet of Things. This adds convenience and data but also expands the number of devices that must be secured.

Standards and coordination

For independently operated networks to work together, they must agree on how to exchange data. Voluntary standards bodies and technical organisations develop and maintain the protocols that make this possible, and address registries allocate unique identifiers so no two devices clash. This coordination is largely non-governmental, which helps the network stay open to new participants, but it relies on good faith and on operators choosing to follow widely accepted practices.

Everyday dependence

The Internet has become critical infrastructure. Banking, shopping, navigation, government services, and much of modern work assume a working connection. That dependence also means outages or attacks can disrupt daily life quickly, which is why resilience, backup routes, and cybersecurity receive sustained investment and attention.

Common misconceptions

Many people use "Internet" and "web" as if they were the same, but the web is just one service running on the Internet, alongside email and others. Another misconception is that a central authority controls the whole network; in reality it is a loose federation of networks. Some also assume the Internet is inherently private, when traffic can be observed unless encrypted, and that it is free to run, although it depends on enormous physical infrastructure.

Key points