KS3 Computer Science Revision
Computer Basics
Algorithms
Networking
the input, output, CPU (central processing unit) and memory are the 4 major parts of a computer
When ever we connect two or more computers together, so that they can communicate with each other, we have a computer network.
Hardware
Software
Connections between computers can be wired or wireless.
Topologies
used to develop and express solutions to computational problems
Decomposition is breaking down the problem into smaller parts.
A set of instructions or commands to complete a certain task
Network Types
Whilst others are connected over much larger areas - these are called WANs (Wide Area Network)
A set of common communication protocols over digital interconnections to share resources provided by network nodes.
Input → process → output
The CPU does the processing
CPU - central processing unit where programs are executed and the components are told what to do
memory- keeps track of the information so that it can be recalled later
in a CPU there is a ALU which does all the maths and logic
Data is transmitted to different computers in the network using packets.
The packets are then sent between computers in the network until they reach their destination.
Sometimes packets get ‘stuck’ and can’t reach their destination.
Application Software
Operating System
Flexible code that runs on a computer to perform specific tasks (a set of instructions) which must be loaded into the computer's storage before executing
The various programs that run on a computer
The software that manages the computer's basic functions
E.G. OSX, Windows, Linux
E.G. Chrome, Office, Games
Some computers are connected over a small area - these are called LANs (Local Area Networks).
We can connect computers together in lots of different ways. The different set-ups for a wired network are known as topologies.
Types of computer
Computer Definition
A computer or machine that that carries out calculations form a set of instructions.
Mobile devices
Embedded systems
Personal Computer
Line
Fully Connected
Bus
Ring
Star
Super Computer
Desktops
Laptops
Server
Tablets
Phones
mp3 players
Cars
Toys
Web Server
File Server
These host websites
Personal storage
When the recipient has received the packet, they will then send back their own message to say that it has been received. This is called the error check.
This forms the basis of the Transition Control Protocol [TCP/IP mode] for sending data via this internet.
Network Security
Network security is the process of taking physical and software preventative measures to protect the underlying networking infrastructure.
Data Size
KB: kilobyte
MG: megabyte
GB: gigabyte
TB: terabyte
PB: petabyte
B: Byte