What is computer hardware?

Core elements include the central processing unit (CPU), random access memory (RAM), storage drives (for example, hard disk drives, solid-state drives) and the system board that connects them. Users interact with computers through input devices such as keyboards, mice, touchscreens and scanners. Output devices, such as monitors, printers and speakers, deliver information to the user. Networking hardware, including routers, switches and network interface cards (NICs), enables system communication.

In contrast to hardware, software consists of programs and instructions that tell the hardware what tasks to perform. While hardware is tangible and performs the physical work of computing, software is intangible and provides the logic and commands that bring hardware to life.

Today, computer hardware extends far beyond traditional desktop computers. It powers everything from enterprise servers and cloud data centers to smartphones, connected vehicles, smart medical devices and other Internet of Things (IoT) technologies. This widespread integration of computing hardware shapes how businesses operate and how people live, work and stay connected. For enterprise business, hardware is more than what’s behind the scenes, it’s the backbone of operations, enabling efficient data flow and driving innovation.

The modern computer hardware era began in the 1940s with massive mainframes used primarily by governments and research institutions. These workstations were expensive and physically enormous, limiting their use to specialized environments. The 1950s and 1960s brought crucial advancements in electronic components, making computers smaller, more reliable and more accessible.

In the 1970s and 1980s, the invention of the microprocessor led to the rise of personal computers like the IBM PC, bringing computing power to individual users and small businesses.

The 1990s and early 2000s saw explosive growth in networking hardware and the rise of the internet, transforming how people communicate and how companies operate. Data centers and enterprise servers became essential IT infrastructure, while laptops and portable hardware devices made computing more accessible and practical.

In recent years, cloud computing has reduced the need for physical infrastructure by shifting storage and computing power to remote data centers. However, these cloud services still depend on massive, highly specialized physical hardware. At the same time, mobile devices, connected sensors and embedded systems have made computing more personalized than ever.

Today, innovations such as AI-optimized processing and edge computing are reshaping how businesses analyze data and deliver insights. Hardware continues to evolve, becoming more powerful, efficient and seamlessly integrated into daily life and work. Quantum computing represents the next frontier, introducing fundamentally new hardware architectures capable of solving problems beyond the reach of traditional systems.

Computer hardware is typically divided into internal and external components. Internal hardware is located inside the computer case and includes components that handle processing power and storage capabilities. External hardware consists of peripheral devices that connect to the computer from the outside to support interaction and expand performance.

All these types of hardware components work together under the control of the operating system (OS)—the primary software that manages the computer's resources and provides an interface for users.

• Central processing unit (CPU): The CPU is the brain of the computer, responsible for carrying out instructions and running calculations. It manages and coordinates most tasks the computer performs. Modern CPUs contain billions of microscopic transistors, which act as electronic switches to process data and run instructions at incredibly high speeds.

• System board: The system board is the main circuit board that connects all internal computer components. It allows communication between the CPU, memory, storage devices and other hardware parts.

• Random access memory (RAM): Random access memory (RAM) temporarily holds data that the CPU actively uses, enabling faster program execution.

• Storage drives (HDDs, SSDs): Storage drives are used for long-term data storage, including files and applications. There are two main types: hard disk drives (HDDs) and solid-state drives (SSDs). HDDs use spinning magnetic disks and are typically slower, but they offer more storage at a lower cost. Alternatively SSDs use nonvolatile flash memory with no moving parts to store data, making them faster, more durable and energy-efficient.

• Graphics processing unit (GPU): The graphics processing unit (GPU), often referred to as a graphics card, is responsible for rendering images, videos and 3D graphics. It’s especially important for gaming, graphic design and tasks that involve visual computation. GPUs come in two forms: integrated (built into the CPU) and dedicated (a separate graphics card that offers better performance).

• Power supply unit (PSU): The PSU converts electrical power from an outlet into usable energy for the computer's internal components, ensuring that each part receives the correct voltage and current.

• Cooling systems: Cooling components prevent hardware from overheating during operation. These systems include heat sinks, which are metal components that draw heat away from processors, and fans, which circulate air to dissipate heat. Liquid cooling systems use circulating fluid to remove heat more efficiently, making them ideal for high-performance systems.

• Expansion cards: These additional circuit boards plug into the system board expansion slots to add usability. Common types include sound cards (for enhanced audio), network interface cards (for wired or wireless networking) and capture cards (for recording video input).

• Input and output ports (I/O): Input/output ports (I/O) allow external devices that connect to the computer for communication and data transfer. Common I/O ports include USB ports, HDMI, Ethernet and audio jacks. These ports support a wide range of external components, from monitors and printers to storage devices and audio equipment.

• Monitor: A monitor displays visual output from the computer, allowing users to interact with software, view media and monitor system activity.

• Keyboard: A keyboard allows users to input text, numbers and commands. Most include function keys, a numeric keypad and shortcut combinations for system navigation.

• Mouse and touchpad: The mouse enables users to control the cursor and interact with on-screen elements through pointing, clicking and scrolling. A touchpad serves the same function on laptops with a flat surface that responds to finger movements.

• Printer and scanner: A printer produces physical copies of digital documents, while a scanner digitizes physical papers or images to be edited, stored or shared electronically.

• External storage devices: External storage devices include USB flash drives, SD cards, memory cards and external SSDs or HDDs. Many of these devices, particularly USB drives, SD cards and external SSDs, use flash storage to provide portable options for transferring, backing up or expanding a computer's file capacity.

• Audio devices: Speakers, headphones and microphones enable sound output and input. These devices range from basic built-in options to high-fidelity external systems for specialized audio needs.

• Networking equipment: Routers, modems and network switches connect computers to local networks and the internet, facilitating data exchange between devices and online services.

• Webcams and cameras: These visual input devices capture still images and video for communication, content creation and security applications.

• Game controllers: Specialized input devices such as gamepads, joysticks and VR controllers provide intuitive control for gaming and simulation apps.

Hardware refers to the physical components of a computer system that perform tasks and process data. Alternatively, software consists of the computer programs and instructions that enable the hardware to carry out specific operations. While hardware provides the foundation, software defines the actions the system takes.

For example, when you run a word-processing application, the software tells the CPU how to display text on the screen and save documents. Similarly, when you play a video game, the software instructs the GPU to render the images, while the hardware processes the data to output the video.

With advancements in software, it’s now possible to create virtual versions of hardware, allowing a single physical system to run multiple virtual environments. This process, known as hardware virtualization, enables more efficient resource usage and adds flexibility to how businesses manage their infrastructure.

By using a hypervisor, which allocates resources to different virtual machines (VMs), organizations can reduce hardware costs, improve scalability and increase operational efficiency. Virtualization has become a cornerstone of modern computing, particularly in cloud environments, data centers and enterprise IT systems. Leading cloud service providers—such as IBM Cloud, Microsoft Azure, Google Cloud and Amazon Web Services (AWS)—depend on hardware virtualization to deliver scalable, on-demand computing resources and deliver modern applications and services.

In a business context, computer hardware refers to the physical parts that support essential operations. Technology infrastructure includes devices such as servers, data storage systems and networking equipment that are critical for managing data, running applications and ensuring reliable system performance.

Enterprise-grade hardware is typically more robust than consumer-level equipment, offering greater reliability, redundancy and advanced management features. To balance performance, security and cost, many businesses now use a hybrid cloud approach, combining on-premises infrastructure with cloud-based services.

One increasingly popular model is hardware as a service (HaaS), which allows businesses to lease or rent hardware from a managed service provider (MSP) on a subscription basis. This solution eliminates the need for large upfront capital investments while ensuring access to the latest technology. HaaS also simplifies maintenance workflows and offers flexibility as IT needs evolve.

As artificial intelligence (AI) becomes more widely adopted in enterprise environments, specialized pieces of hardware—such as GPU servers and AI accelerators—are becoming a standard part of business infrastructure. These components support advanced analytics, machine learning (ML) and process automation, enabling greater efficiency and innovation.