Most of the processing and storage devices show up “inside the PC.” the following are the major elements will find inside the system housing, or case :
Processor/CPU
The processor (also known as the central processing unit, or CPU) is the “brains of the organization,” so to speak. It is designed to do very few things, but to do them extremely quickly. The processor performs a limited set of calculations based on requests from the operating system and controls access to system memory. Processor speed is measured in several different ways, including clock cycles or megahertz (MHz) and gigahertz (GHz), and millions of instructions per second (MIPS). Any of these measures give you an estimate of the processor’s speed/power.
Storage devices
Storage devices on computer are responsible for storing data, such as the operating system, applications, and actual output of applications or user data. Depending on the amount and type of data, the seven basic types of devices to work with are
- Floppy drives,
- Hard drives,
- Solid-state drives (SSD)
- Hybrid drives
- Optical drives
- Magnetic tape drives,
- Flash drives
Memory
Memory is a solid-state (that is, no moving parts) storage medium. It can take many forms, such as RAM (random access memory), flash RAM, ROM (read-only memory), or EPROM (erasable programmable ROM). Access time for RAM is measured in nanoseconds (one-billionth of a second). When memory is discussed, it usually refers to RAM, which is the computer’s primary working memory. RAM is a form of storage albeit typically temporary storage. Many people might not think of RAM as a storage medium because it is volatile and loses its information when power is removed, but temporary storage is still storage.
System boards
The term system board describes any number of circuit boards that make up the internals of computer, but it is used most often to describe the motherboard.
The motherboard is the main board in computer that contains the BIOS chips, RAM, I/O ports, and CPU. This board maintains the electrical pathways that enable all other components to communicate with each other inside the PC.
Power supply
The power supply does exactly what its name suggests: It supplies power to the rest of the components in the computer. The power supply takes 120 or 240 volts (depending on the country ) of alternating current (AC) from electrical outlet and converts it to 3.3 V, 5 V, and 12 V of direct current (DC). It contains a number of leads that supply different voltages for different types of devices (such as hard drives, PCIe expansion cards, and floppy drives — which you will not likely have a need for).
Adapter cards
Adapter cards allow to adapt computer to another role (such as controlling assembly line robots) or to add specific functionality to computer (such as printing). The most common adapters are now integrated into most motherboards. These components include display, network, keyboard controller, mouse controller, serial ports, parallel ports, FireWire ports, and USB ports.
Cooling system and fans
As electricity moves through any circuit, heat is generated, which is illustrated by looking at a simple circuit that contains an incandescent light bulb. As electricity moves through the bulb, the filament heats to glowing. Heat is also generated while electricity moves through the integrated circuits that are contained in most of the components of the computer. In addition to these fixed integrated circuits, hard drives contain moving parts that generate heat from friction. These components generate a large amount of heat, which needs to be removed from the critical components to prevent them from failing early in their careers.
Firmware and chipsets
People like to keep their world in a perceived state of order to give themselves a sense of control. This is often seen by how we classify everything we see or work with into categories. Many of these categories seem very distinct until something comes along to challenge our opinions, and then the waters become murky.
One of these murky areas is the distinction between hardware and software, which at one point were thought to be distinct and separate. Software is programming code that is stored on your disk or on some other form of media. Hardware refers to the physical components — boards, peripherals, and other equipment — that make up your computer.
Firmware fills in a middle ground between software and hardware, where the distinct line begins to disappear. Firmware is programming code (software) that is contained in or stored on the IC (integrated circuit) chips (hardware) on your computer. This combination of hardware and software makes up the BIOS on several different devices, with settings stored in CMOS or flash RAM. This firmware is tied to the function of the IC chips that it is working with; in the case of a network card, firmware would manage network or PXE (Preboot eXecution Environment) boot functionality of the card
Most modern motherboards have a series of IC chips and firmware that work together to control the integrated functions of the motherboard. The compatibility of these chips and the code that ties them together is provided by a single supplier, and this group of chips is referred to as a chipset. Intel and VIA Technologies produce popular chipsets.
BIOS
BIOS is short for basic input-output system. The BIOS is actually software that is stored on a ROM chip on the motherboard. Most systems today use a flash EPROM to store the BIOS so that the user can update the programming code in the BIOS
The BIOS is responsible for controlling or managing low-level but extremely important processes like the POST (Power-on Self-Test), the boot process, and the interaction of components on the motherboard.