How the Domain Name System works and how it provides a directory for the internet

Domains were like real estate in the dot-com era

In the early days of the World Wide Web, users needed to type URLs directly in the search bar to navigate to webpages (as opposed to the more general keyword search that browsers use now). This made simple, short, and intuitive domain names a hot commodity. So having a domain name, like Pets.com or Rent.com, that was easy to find and understand was like owning prime real estate on the WWW. (Some users may experience a paywall.)

An overview of the World Wide Web, which is often confused with the internet

When users create a website, they organize content and store it on a web server—one of various types of hardware that make up the internet—in web languages, such as HTML and JavaScript. When visiting the site, a web browser translates these languages into text and other media for consumption.

An explanation of TCP/IP, which helps transmit data across the internet like a club sandwich

The system consists of several layers—application, transport, internet, and network—each responsible for specific tasks. These include interacting with a web browser, checking for errors, sending packets of data across various networks to avoid congestion on their way to a destination address, and managing the transmission of information across hardware, such as an Ethernet cable.

View the ecosystem of global services, organizations, and agencies behind the internet

Through an open, transparent, and collaborative model built on open standards development and shared global ownership, the internet is kept freely accessible amid evolving international policies. Key organizations, such as IANA, which allocates IP addresses and fulfills administrative functions for the Domain Name System, function as non-profit organizations.

Instead of .com or similar, web addresses on the dark web end in 'd.onion'

Since the latest version of the onion routing protocol, dark web domain names consist of a random set of 56 alphanumeric characters followed by .onion (e.g., propublica.org → p53lf57qovyuvwsc6xnrppyply3vtqm7l6pcobkmyqsiofyeznfu5uqd.onion). The last character is always "d" due to the encryption algorithm's requirements.

Learn how governments around the world restrict internet access for their citizens

Various countries around the world, including China, Russia, and Iran, control their local DNS infrastructure, allowing them to block access to online content by preventing the internet "phone book" from finding the IP addresses for specific URLs. Government-controlled internet service providers can also cut off access entirely or throttle specific traffic.

Minor technology failures can spiral into massive internet outages

A mix of centralized cloud infrastructure and legacy protocols leaves the internet susceptible to downtime from minor cyberattacks or software bugs, infrastructure damage caused by extreme weather, and human error if a DNS service provider—the internet's phone book—or a backend system, such as Amazon Web Services, were compromised.

The Deep Space Network keeps NASA linked to spacecraft billions of miles away

NASA's DSN is a global system of giant radio antennas that receive data from faraway spacecraft like Voyager 1 and the James Webb Space Telescope. It is sensitive enough to detect a signal as weak as a single light bulb from billions of miles away.

See how computer memory really works—from binary bits to modern RAM

The video explains how computers store information as 1s and 0s, how RAM functions as fast working memory, and why systems utilize different types of storage. The video demonstrates how this process enables computers to operate.

Microsoft's Azure cloud computing platform serves customers in 140 countries

Rather than owning and maintaining hardware on-premises, cloud computing enables users to access large reserves of storage and processing power over the internet, much like customers connect to a utility provider rather than generating their own electricity. This centralization also standardizes security tools and updates.

Visualizing the growth of botnets

Botnets are a network of computers that have been infected with a variant of malware that coordinates and leverages them for automated mass attacks such as data theft and crashing servers. This interactive map highlights where botnets have been located between 2014-2020.

Ads follow you around the internet through cookies

A technology called “cookies” enables advertisers to essentially team up and follow your behavior around on the internet. This video explains why it seems like ads seem to follow you as you go from website to website—as well as data privacy advocates’ war against cookies.

Manholes connect underground sewer and water drain pipes

Wherever a portion of sewer is connected to another, a manhole is built. These serve both as access points for maintenance and as connectors for the system. This video shows how crucial manholes are for proper sewer functioning.

The platform's ease of use relies on a complex architecture

Hitting "play" on Netflix is easy, but it triggers a multistep process that fetches the selected content, converts it for your screen, and finds the closest server to deliver it in the highest quality.

How hash functions encrypt stored passwords and can be enhanced with 'salt'

Hash functions convert text into unique, random sets of characters, a process that is computationally expensive and time-consuming to undo. Because hashed outputs for many common passwords are publicly listed, some sites use a salt—additional characters appended to a password—before hashing to produce an output that is not known. When entering a password, it is salted and hashed, then checked against the database for a matching hash before permitting login.

Data centers require interconnected server- and building-level cooling systems

Computer equipment can be cooled by circulating cold air or water through the equipment racks, siphoning the heated fluid into a heat exchanger. This exchanger transfers thermal energy to building cooling systems, which can dispose of the heat by evaporative cooling—the way humans cool off by sweating—or via air conditioning.

193 nations are members of the United Nations

The UN's Member States webpage provides an alphabetical list of all 193 member countries, along with the exact dates they were admitted. Take a look at how the UN has expanded over time and understand each nation's place in the global organization.

DNA's four-letter blueprint makes the variety of all living things possible

The proteins responsible for cellular functions and an organism's traits are built outside of a cell's nucleus from RNA—single-stranded molecules created by reading the information in DNA. DNA's double-stranded structure makes it more stable and allows RNA to be made from either of its complementary strands.

What are neural networks and why do they matter?

Learn how a neural network works, why it matters, and how it can be trained to recognize patterns, classify data, and forecast future events.

What is the Fediverse?

The "fediverse" is a league of like-minded apps looking to make our digital identities—including posts, followers, activity—move seamlessly between networks. It's a decentralized approach, making various social networks interoperable in contrast to Facebook and Twitter, where content is platform-specific. The fediverse provides stability and control to users. Learn more here.

How radio works

Antennae tune a radio to a particular frequency (determined by the listener on their radio's dial) while tuning out all the other stations being broadcast. AM, short for amplitude modulation, and FM, short for frequency modulation, decode audio signals differently, leading to differences in sound quality and the distance a station can travel.

What we learned about Google

Google processes over 8.5 billion searches every day—more than the number of people on Earth. This short breakdown covers how the company evolved from a Stanford research project into a global tech leader, with products like YouTube, Gmail, and Android reaching billions worldwide.

Understanding the structure of the Chinese phonetic alphabet

Translating Chinese names from Chinese to English characters is a complex process, one in which the original name’s meaning can become muddled. This article uses graphics to explain the structure of Hanyu Pinyin, the most commonly used Chinese phonetic alphabet. Visualize how the Pinyin romanization system can lead to name ambiguity, and therefore make it challenging to identify individuals based solely on Pinyin.

Human anatomy 101: the body's systems

Human life is made possible by the body's ten major systems, which maintain homeostasis by responding to incoming sensory and biochemical input. Each system must work independently and collaboratively for the body to maintain health and respond appropriately to its internal and external environments. The bones of the skeletal system, for example, give the body its shape and protect organs while also facilitating movement with the muscular system.

Search the official trademark database

The official trademark registry is managed by the United States Patent and Trademark Office. The registry shows the trademark's status, the owner, and the trademark's serial number.

Discover the catastrophic consequences of a failure of the US electrical grid—something that is more likely than many Americans think.

When you complete a CAPTCHA on a website to prove you are human, you may be unknowingly training algorithms for self-driving cars, whose systems require training data to help identify crosswalks, bicycles, and other outdoor objects.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

According to the physics of black holes, our 4D reality may be a hologram—a projection of information coded on a 2D surface on the edge of the universe.

All rainbows are 'raincircles' caused by water droplets separating white sunlight into a spectrum of colors, but Earth's surface blocks the bottom half of the circle from our line of sight.

Hear about the 250-year history of the United States Postal Service, complete with some of its strangest deliveries, important innovations, and the figures that made it an American institution.

While the sun's gravity keeps the planets in orbit, their gravity also pulls on the sun, causing it and everything else in the solar system to orbit around a mutual balance point called the barycenter—the true center of the solar system.

How Amazon operates a 'flywheel' business model, a self-reinforcing cycle that drives continuous growth

Stanford built a Google Maps for the Roman Empire, revealing how much it cost to travel in the ancient world

The name 'Silicon Valley' arose from the founding of Shockley Semiconductor Laboratory in Fairchild Semiconductor in 1956-57, founded near Stanford University in Palo Alto

Chaos theory—informally known as the butterfly effect—is the reason why weather forecasts are presented with probabilities rather than certainties.

The Nasdaq's 'Magnificent 7' companies are responsible for roughly 40% of the Nasdaq 100 index's gains, while the remaining 93 companies account for the other 60%.

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

Explore the animals that populate the depths of the ocean, from fish and coral in the first few hundred feet, all the way down to the bottom of the Mariana Trench.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

The US Constitution is widely regarded as the longest-standing written national constitution still in force—see how it has influenced rights worldwide.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

El Niño, Spanish for 'the boy,' was named after Jesus Christ because the phenomenon resembled the weather changes observed around Christmastime.

The term 'algorithm' originated from the Latinized name of al-Khwārizmī, a 9th-century mathematician whose works introduced Arabic numerals and the decimal-based numeral system to Europe and whose treatise 'Al-Jabr' gave algebra its name.

An initial public offering or 'IPO' is the process of a private company becoming public by putting shares of the company on the stock market for purchase.

Learn how monoclonal antibodies, which mimic the body's antibodies, can fight diseases like Ebola.

The Mona Lisa's celebrity status and repeated restorations have obscured what made the painting so revolutionary for its time

20,000 letters to the advice columnist 'Dear Abby' provide insight into prevailing sex, religion, and LGBTQ fears, anxieties, and concerns from the 1950s onward.

Legendary architect Frank Lloyd Wright designed the SC Johnson headquarters in Wisconsin, aiming to make a cathedral-like workplace

A small portion of The Winstons' 'Amen, Brother,' an obscure '60s gospel record, is the basis for thousands of hip-hop tracks, making it one of the most sampled records ever that's informally known as 'the Amen break.'