LC CS - Computer Systems

Computer Systems

A system is a combination of many connected parts all working together to achieve a common goal.

Computer Architecture

A computer's architecture is a specification of how a computer's different parts are physically and logically laid out or connected.

Von Neumann Architecture

The computer architecture described by John Von Neumann in 1945, which is still relevant today.

CPU

The central processing unit which executes instructions and carries out computations on data.

Control Unit

The control unit directs the operations of the CPU.

ALU

The Arithmetic/Logic Unit is where the arithmetic and logical processing takes place.

Registers

Temporary storage locations that the CPU can access very quickly when carrying out operations on data.

Fetch Execute Cycle

The cycle where the CPU fetches the program's next instructions from memory, decodes them, and executes them.

Clock

The timing source that controls operations in the CPU, determining the speed of the CPU.

Bus

Connects the CPU and memory, with a computer typically having more than one bus.

Memory

Modern computers can store programs internally in memory, as well as input and output data.

RAM

Random Access Memory is temporary memory that holds data and instructions of the currently executing program.

ROM

Read Only Memory is non-volatile memory that retains its contents regardless of power status.

Secondary Storage

Devices used to store data persistently, regardless of whether the computer is powered on or off.

Motherboard

A circuit board that devices are physically mounted on, typically including the CPU, main memory, and hard drive.

Binary Code

Used to represent all information, where on and off (1 or 0) are represented by the presence or lack of an electrical signal.

Current

The flow of electrons from one place to another.

Voltage

The difference in charge that causes an electron to experience a force.

Resistance

A measurement of how much material resists the flow of electric current.

Transistors

Tiny electric switches that allow a small current to switch on or off a larger current.

Resistors

Devices that reduce current flow.

Capacitors

Devices that store electrical energy in the form of electric charge.

Logic Gates

Electronic circuits that process data, consisting mainly of transistors.

Operating Systems

A collection of programs that control the operation of the computer and its attached devices.

Functions of an Operating System

Includes managing data from input devices, controlling program locations in memory, and providing user interfaces.

The Internet

A network of connected computers that dates back to 1969.

World Wide Web

A collection of documents linked to each other, using the Internet as a transmission medium.

Client-server Model

A model where a computer requests information from a server, which then transmits the resource.

Communication Protocols

A set of rules describing how data is transmitted across a network.

HTTP

Hypertext Transport Protocol, a request-response protocol for resource requests.

TCP

Transmission Control Protocol that ensures reliable transport of binary information between computers.

IP

Internet Protocols that handle the creation of data packets and their routing around the network.

VOIP

Voice over Internet Protocol, methods designed to deliver voice data and associated data.

Internet Hardware Components

Hardware that connects end-user devices in the global network of computers.

Cloud Computing

Storing, processing, and accessing data, programs, and services over the internet from dedicated servers.