All computers are defined by their ability to input, store, process, and output data

A timeline of computer history

The earliest computers bear little resemblance to the computing devices that most people rely on today. This timeline graphic from the Computer History Museum tracks their evolution, from the early days of bulky mainframes that only experts generally used through to the personal computing revolution and on to the modern mobile era. Readers will learn important context ahead of the next major computing platform shift.

More than 2,000 years ago, a hand-powered model of the solar system called the Antikythera mechanism—the oldest example of an analog computer—could predict solar eclipses.

An explanation of Turing machines—the foundations of digital algorithms and computers

The device reads data, overwrites or ignores it, and then moves on to the next piece of data based on a set of programmed rules. By imagining this data as zeros and ones—binary that makes up computer code—Turing machines became the theoretical models for how any algorithm could be run on a computer if the procedure could be coded into a set of digital rules.

Today's massive data centers evolved from single-room mainframes

Punch card computers from the late 1940s were used to store and process a company's data locally before the advent of desktop computers. As the amount of data and company sizes increased alongside the miniaturization of technology, mainframes were replaced by local server rooms and external facilities with interconnected servers running cloud-based and AI software.

With many smaller computing cores, graphics processing units process many identical tasks in parallel, whereas central processing units have fewer, larger cores built to handle a wide variety of more complex tasks sequentially.

A simple explanation of semiconductors

Semiconductor chips are electronic devices that store and process information. Today they can contain billions of microscopic switches on a chip smaller than a fingernail. The article provides a quick overview of how the devices work and how they've provided the backbone of the computer age.

Semiconductor chips are electronic devices that store and process information

They can contain billions of microscopic switches on a chip smaller than a fingernail. An article provides a quick overview of how the devices work and how they’ve provided the backbone of the computer age.

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.

Before transistors, which regulate the flow of electricity, vacuum tubes—glass tubes containing no gas that resemble light bulbs—served as the electronic switches in computers.

Logic gates—digital versions of conditional statements, such as 'if 0 and 1, then 1'—are specialized circuits that combine multiple digital signals, like the binary code representing numbers, into a single output, thereby allowing machines to perform math.

Turing machines consist of an infinite tape, a read-write mechanism and instructions

Based on the information the mechanism reads on the tape, the machine follows the applicable instruction (e.g., if you read a 1, write a 0) and may proceed to the next cell of data. Given enough time and memory, Alan Turing proposed such a machine could perform any computation.

Transistors in traditional computers are physically limited to atomic scales

As computer parts shrink, transistors—tiny switches that control the path of electrical signals—become obsolete because electrons can quantum tunnel through switch barriers. This makes quantum computers, which take advantage of quantum effects, an enticing alternative.

A brief history of artificial intelligence

The concept of artificial intelligence and what it may mean for humanity has evolved as computer technologies have grown increasingly powerful through the decades. Beginning with the first (massive) computers in the 1940s, scientists have sought to make the machines as intelligent as humans. But it wasn't until computing power made exponential gains have computers begun to imitate human behavior.

Qubits let quantum computers process massive datasets all at once

The quantum phenomena of superposition and entanglement enable qubits to act in 0 and 1 binary states simultaneously and influence each other instantly. These features give quantum computers incredible power, though keeping them stable is a major challenge.

Quantum computers use qubits to solve problems much faster than classical machines

Unlike regular computers, where each bit is either 0 or 1, quantum computers use qubits, which can simultaneously be both—allowing for massive parallel processing power. Google’s quantum processor once solved a problem in seconds that would have taken a supercomputer 47 years.

Explore an online gallery highlighting the importance of graphical user interfaces

Before the Macintosh, computers were primarily used in offices and required users to type complex commands to perform tasks. Apple followed the device with the LaserWriter printer, bringing graphic production to at-home artists and designers.

Graphics processing units, which process large amounts of data in parallel, have become the foundational hardware for AI systems that rely on hardware capable of processing millions of text parameters simultaneously.

Transistors are the foundational components of integrated circuits and microchips and manage the processing of electronic signals by controlling the flow of electricity.

Explore how the most commonly used words in the English language have changed from the 1950s to 2023.

A breakdown of algorithms, how they are constructed, and their applications

Algorithms are instructions for accomplishing a goal and typically take the form of a step-by-step procedure. Given the conditions, these procedures can take various paths, increasing an algorithm's complexity. While traditional computer algorithms are programmed to account for all possible scenarios within a given process, machine learning systems build their own rules from data-driven patterns.

Grace Hopper warned against prioritizing hardware purchases in future computing

Foreseeing the rising volume of data and the increasing demand for its processing and access, she advocated that organizations first map the total flow of information they require and then choose infrastructure to support it, rather than wastefully spending on the fastest computing technology and forcing software to compensate for unnecessary hardware or incorrect data.

Quantum computers harness weird physics to explore unsolvable problems

Classical computers manipulate bits as either 0 or 1, but quantum computers use qubits to hold combinations of both, enabling new algorithms. This new approach could one day help with breakthroughs in medicine, chemistry, and AI.

The first compiler to facilitate communication with computers was developed by Grace Hopper

The A-0 program linker automatically translated mathematical symbols into machine-readable binary code. Although it took two years for computer executives to get on board with the idea, the technology was foundational to future programming languages that allowed computers to understand commands written in word-based languages.

The history of graphics processing units began with hardware for displaying visuals in arcade machines, but the transition to 3D graphics led to the microchips and software that power today's AI data centers.

DNA computing allows for storage and processing of massive amounts of data

Although costly and less efficient for simpler tasks, as of 2025, DNA could hold 455 exabytes of data with near limitless parallel computation potential in small data centers. Every movie ever made would fit inside the volume of a single sugar cube.

View the layout and components that make up a typical data center

Alongside server rooms for the storage, processing, and transmission of data, data centers include climate control systems to manage the heat generated by microchips, backup systems to ensure systems can run during power outages, offices for on-site personnel, and monitoring and security stations to provide continuous protection against physical threats.

English mathematician Ada Lovelace wrote the first computer algorithm a century before computers existed and hypothesized that computing devices would one day be able to compose music—foreseeing the generative AI systems of today.

COBOL was partly derived from Grace Hopper's FLOW-MATIC programming language

The Common Business-Oriented Language was developed for business data processing, supporting precise decimal calculations and an English-like syntax. Able to work across operating systems and hardware environments, COBOL and its newer versions support 80% of in-person credit card transactions and 95% of all ATM transactions.

The internet explained at five levels of difficulty, from protocols to internet flattening

Resembling a roadway with traffic laws that all cars must follow, the internet is the hardware that connects a source to a destination, and these connections must follow specific software rules. Although data had to travel through about 10 networks to reach a destination in the past, data centers increasingly consolidate traffic, just as a highway does for cars, to improve data speeds.

Quantum computers can simulate nature more effectively than classical computers

Ordinary computers struggle to simulate quantum fields due to entanglement, but systems built from those elements can model the complexity. Systems using particle in more than two states—qudits—have successfully modeled 2D electromagnetic fields and done so more efficiently.

Integrated circuits come in digital, analog, or mixed types

Each type can be further divided based on application, technology, and integration level. Digital ICs are used in computer memories and microprocessors, while analog ICs process continuous signals within sensors, including temperature, light, and sound.

The Antikythera mechanism: The oldest-known analog computer

A device now considered the world's oldest computer was pulled from a shipwreck more than 120 years ago. Known as the "Antikythera Mechanism," it is now believed to have allowed precise tracking of astronomical positions, and its sophistication overturned understanding of Ancient Greek capabilities.

Moore's Law came from observing exponential computing growth in the 1960s

In 1965, Gordon Moore, cofounder of Intel Corporation, observed a four-year trend of constant growth rate in computing power. Hypothesizing the trend would continue, his observation became the benchmark that the computing industry has worked to maintain for 60 years.

An overview of 12 fundamental types of algorithms and the uses for each

These include search algorithms to quickly process and find important information, cryptographic algorithms to secure communications, randomized algorithms—such as Monte Carlo simulations for estimating probabilities of outcomes—and greedy algorithms, which make optimal choices based on available data in a step-by-step fashion, as seen in navigation apps.

Misunderstandings about how quantum computing works may have overhyped their ability

Quantum computers are often viewed as machines that can solve all problems instantly by trying every solution simultaneously. Instead, they amplify correct answers and cancel out wrong ones, which only works for specific kinds of problems with special structures.

Computational and biological systems share fundamental principles, like randomness

Proposed by Alan Turing and John von Neumann, the concept originates from how DNA and computers run by executing encoded instructions in parallel. The advent of AI and the temperature parameter has seen neural networks mimic the randomness of protein encoding.

The history of malware includes computer viruses, worms, trojans, and ransomware

Some of the earliest significant pieces of malware—the Creeper worm and the Elk Cloner virus—displayed silly messages to users without causing major harm. As computer science has advanced, malware has become more easily spread, incorporated social engineering to manipulate users, targeted infrastructure systems, and been used by governments for virtual espionage.

A historical tree of technological advancement

Starting from stone tools millions of years ago and culminating in today's cutting-edge tech, this thorough genealogy lays out how humanity has progressed in its use of tools over thousands of years. See descriptions, links to further info, and how each tech fits in the larger tree.

Machine learning lets computers learn from data instead of relying on programming

ML is a core part of artificial intelligence and is foundational to applications like chatbots, fraud detection, and self-driving cars. Businesses are also adopting it to improve efficiency and identify patterns in data, though the latter may be inaccurate.

An overview of Linux, from the foundational program to its related operating systems

The Linux kernel, which bridges hardware and software, serves as the basis for many fully customizable operating systems, whose components can be modified or removed to optimize performance or reduce bloat on devices with limited resources. This has made these OSes useful for low-power devices like smart thermostats, as well as for powerful supercomputers that require computational efficiency.

The Macintosh popularized GUI and mouse navigation for personal computing

A graphical user interface that utilized windows, icons, and pull-down menus, rather than text-based commands, contributed to the device's success after its January 1984 launch. Its original sound system—capable of playing four voices—was developed after non-technical staff suggested the machine should play music.

Personal computers became more common in the late 1970s, making working from home more viable

As the internet and email became more popular in the 1990s, more infrastructure that would eventually support remote work was created. But the practice was still relatively uncommon until the COVID-19 pandemic, when white-collar workers first took to working from home en masse.

Since computers rely on the distribution of electrons in microchips to represent binary code, cosmic rays and ionizing radiation from radioactive elements can introduce software errors by detaching electrons from atoms.

Mac settings have evolved from minimalism to chaotic clutter

The 1984 Mac control panel featured wordless icons, sliders, and desktop pattern editors, highlighting early experimentation in graphical user interface design. This software charm and personality gradually disappeared as Apple enforced visual and functional consistency over time.

Why atoms are used to keep track of time and define the meaning of a second

Small variations in the production of human-made devices, such as mechanical watches and pendulums, make them unreliable for the ultraprecise timekeeping required by modern technology, including financial transaction timestamping and GPS. Because atoms obey fundamental laws of nature and never wear out, their light emissions when energized provide a consistent timekeeping signal.

Noise and instability made quantum computing seem out of reach for decades

Recent advances in error suppression, mitigation, and correction are allowing quantum computers to perform practical tasks that challenge classical machines. IBM’s 2016 launch of its first cloud-accessible quantum computer attracted over 22,000 users in its first month alone.

Distinguishing between Web 1.0, 2.0, and 3, all made possible by the internet

The World Wide Web began as read-only, static webpages on Web 1.0, where data could not be entered. With Web 2.0, the online interface became a read-write space for data entry, post creation, and forum participation, among other activities. Web3 is intended to be decentralized, user-owned, and built on blockchain technology.

When buying a custom computer, selecting integrated graphics is more affordable, but a dedicated graphics card should be considered for CAD, video content creation, high-end gaming, and 3D modeling.

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.

FLOW-MATIC was the first programming language resembling the English language

As part of the team working on UNIVAC—the first commercially produced electronic digital computer in the US—Grace Hopper helped develop the system that enabled nonprogrammers and businesspeople without a strong mathematics background to use the machine effectively, thereby enhancing the computer's commercial viability.