Computer Hardware and Software: A Comprehensive Guide

Computer Hardware

Hardware is the physical part of the computer.


The motherboard is the main circuit board of a computer. Other components, such as the microprocessor, are inserted onto it. It also houses communication ports for peripheral devices, video, audio, and network devices.

  1. Chip and battery for BIOS: This integrated circuit (chip) stores the computer’s booting program. It is usually labeled with “BIOS.”
  2. Microprocessor: Plugged into a socket, the microprocessor is responsible for processing data and controlling other devices. A fan helps dissipate heat.
  3. Connectors (slots) for RAM modules: These slots hold the RAM modules, which provide temporary storage for data.
  4. Connector ATX: This connector joins the motherboard with the power supply.
  5. IDE connectors (older and wider) and SATA: These connectors connect the motherboard to storage units (such as hard disks, DVDs, and DVD recorders).
  6. Internal connectors PCI expansion slots and AGP: These slots interconnect graphics cards, sound cards, network cards, etc.
  7. External peripheral connectors (also known as ports): These ports connect input/output peripherals to the motherboard:
    • RJ-45 network connector: Enables internet connection.
    • VGA graphics connector: For the monitor or projector.
    • Connectors DVI-VGA graphics and HDMI: For connecting to displays.
    • Parallel port: For printers, scanners, etc.; largely in disuse (USB is now used).
    • ATX and Molex connector and Molex-SATA connectors: For power supply.
    • USB connector for various uses (it allows interconnection with practically any device): Pen drives, mouse, etc. It can be USB 2.0 (standard) or USB 3.0 (at a speed ten times higher). There is also the mini-USB (for MP3 players, cameras) and micro-USB (for smartphones).


The microprocessor is mounted on a socket on the motherboard. It normally has a fan and heat sink above it to cool it down, as excessive heat can cause the computer to malfunction. It is characterized by its working frequency, measured in Hz, which determines its operating speed. A modern computer has a microprocessor operating around 5GHz (5 billion logic operations per second).


There are three types of memory:

  1. RAM (Random Access Memory): Enables reading and writing, but is volatile, meaning the information stored in it is lost when you turn off the computer or when the power supply is turned off. It is inserted into modules on the motherboard.
  2. ROM (Read-Only Memory): This is non-volatile memory, meaning data is retained even when the computer is turned off. This makes it ideal for storing computer boot routines (stored in the BIOS).
  3. Cache memory: This type of memory is faster and has a lower capacity than RAM. It acts as a bridge between the microprocessor and RAM, and contains frequently used data in basic logical operations (usually within the microprocessor chip itself).

Storage Units

Storage units, also known as storage devices, can be:

  1. Internal storage drives: These include hard drives, which can be:
    • Magnetic hard drives: Use a moving head to read and write data.
    • Solid state hard drives: Store information in memory microchips and have no moving parts, making them faster and more energy-efficient, but with a limited lifespan based on a certain number of operations.
  2. External storage drives: These include CDs, DVDs, Blu-Ray disks, USB flash drives, micro SD cards, etc.


  • Primary partitions: A hard drive can have up to four primary partitions, each with its own file system (NTFS for Windows, Linux Ext3, etc.). The operating system can detect and assign a drive letter to each primary partition.
  • Extended or secondary partitions: Used to contain multiple logical units inside. It serves to overcome the limitation of having only four primary partitions. There can be only one extended partition on a hard drive.
  • Logical partitions: Occupy a portion within the extended partition, or all of it, which has been formatted with a file system. At most, there may be 64 logical partitions in an extended one. (For Linux, it’s different, with a maximum of 15, including the four primary.)

Computer Software

Software is the logical part of a computer that makes its operation possible. It includes both the operating system and the programs and applications we use.

When the computer is turned on, the first software that runs is the BIOS (Basic Input/Output System). The BIOS contains the boot program, performs a memory check, and checks communication between the motherboard and peripherals. When the BIOS has finished its task, it hands control over to the operating system.

Operating Systems

Operating systems allow communication between the user and the computer. They also control the operation of hardware and computer programs. Other functions include enabling users to share data and devices (such as a printer).

The most commonly used operating systems are Windows (in its different versions: Windows 8, 10, Vista, XP…), Linux (Ubuntu), and macOS. There are also operating systems for mobile devices (phones, tablets) such as Android and iOS.

Programs and Applications

Programs are lists of instructions that a computer can interpret and execute, such as the programs stored in the BIOS.

Applications are programs designed to facilitate a particular type of work, such as a word processor, a spreadsheet, a database, or a presentation generator.

There are specific applications for mobile devices that take up little space and are easy to download from online stores (like Google Play or the App Store). These applications are specifically designed for mobile devices, with features such as lower power consumption, smaller screen optimization, and touch interaction.


A network is a set of computers and devices interconnected for the purpose of sharing information and resources (hard drives, printers, internet connection, etc.).

In all networks (or communication systems) you will find an information transmitter (which encodes information) and a receiver (which decodes the information). The information travels through a channel or communication line.