The CPU is the central part of your PC. It sockets directly into the motherboard and is like the brain of your computer.
Storage devices are used for installing programs and saving files. PCs have 2 common types of internal storage devices: hard disk drives (HDDs) and solid-state drives (SSDs). Both are nonvolatile memory devices.
Motherboard
The Motherboard is the central backbone of a computer, on which other modular components like CPU, RAM and hard disk are installed. It also acts as the platform on which expansion slots can be used to install add-in devices and interfaces.
The little Pm25LD512 chip highlighted in blue on this motherboard is a flash memory device that saves the BIOS settings when the motherboard is powered off, so that the user doesn’t have to re-enter them every time they power up their PC. All modern motherboards have this type of memory.
This motherboard has 2 memory controllers, each of which handles two sticks of DRAM – hence it has 4 sockets in total. This allows the system to use dual memory channels, which improves performance in graphical computing tasks.
CPU
The central processing unit – or CPU, for short – is the brain of your computer. It solves all of the sophisticated algorithms and programming your PC does while running programs and web browsers.
The CPU fetches program instructions from memory (called a main storage device) over an internal bus called the instruction bus, and then decodes them into signals that tell the rest of the processor what to do. It then executes those instructions. The outputs of the instructions pass through the arithmetic logic unit to be stored in primary memory or other secondary storage devices.
The CPU’s registers are high-speed internal memory-storage units, and it has an internal clock that synchronizes all the parts of the CPU. The clock speed of the CPU is the number of clock pulses it performs every second – commonly referred to as its “clock rate”. This measures how fast the CPU can process instructions.
Graphics Card
Graphics cards, also known as video cards or GPUs, take instructions from the computer’s CPU and translate them into a visual rendering on the monitor. This can include everything from numbers and words in a spreadsheet to images on a webpage, video frames for TV shows and movies, and even 3D graphics.
The card’s RAM (random access memory) stores information about each pixel and where it should be displayed on the screen. The card then sends this data to the monitor over a cable. High-end cards can process tens or hundreds of images per second to make sure everything appears smooth and clear. They help make gaming, ray tracing and other graphics-intensive tasks much more smooth and can reduce the load on the CPU.
Optical Drive
A computer’s optical drive is used for CD/DVDs/BDs reading and writing. It is also called an ODD or a disk drive and can be divided into internal and external ones according to their connection method.
A disc has tiny bumps and pits on its surface that store digital data, and the Optical Drive reads these marks using a laser. There are a few parts to this, including a prism and first focusing lens that direct the laser beam at the disc. Then there is the main photodiode, which senses the light reflected from the disc.
Older type Optical Drives included the CD-ROM Drive, which could only read compact discs, while later models added DVD-ROM drives, as well as the more versatile Blu-ray Disc (BD) drive. Currently, Optical Drives are used to install systems and games on computers, and for storage purposes such as backups.
Hard Drive
The hard drive, or “hard disk” as it’s often called, is where the actual data is stored in your computer. It has a series of platters that are divided into compartments, each with a fixed number of bytes in a sector.
The platters spin at high speeds, and the accuator arm moves across them to read data. It’s a delicate process, and the head can be damaged by even the slightest contact, like a speck of dust.
The actuator arm’s movements are controlled by the controller board, which interprets data sent to it from the CPU. The system then writes information to the appropriate track on the platter. If the data is spread out across multiple tracks, it will slow down the read time.