Computer Science Revision

Computer Science Revision

1. CPU

   • Clock Speed
     • The clock speed measures the number of cycles your CPU executes per second
   • Cache
     • temporary memory
   • Cores
     • Multiple cores allow PCs to run multiple processes at the same time with greater ease, increasing your performance when multitasking or under the demands of powerful apps and programs.

2. Computer Threats

   • Malware
     • A file or code, typically delivered over a network, that infects, explores, steals or conducts virtually any behavior an attacker wants
   • Social Engineering
     • Social engineering is a manipulation technique that exploits human error to gain private information, access, or valuables.
   • Brute-Force-Attack
     • A brute force attack uses trial-and-error to guess login info, encryption keys, or find a hidden web page. Hackers work through all possible combinations hoping to guess correctly.
   • SQL Injection
     • Common attack vector that uses malicious SQL code for backend database manipulation to access information that was not intended to be displayed.
   • How to prevent them
     • Encryption
     • Anti-Malware softwares
     • Passowrds
     • Firewalls
     • User Access Level
       • Define what information the different users on your account can access and edit.

3. Internet

   • Router
     • Connect various networks simultaneously and it works in the network layer.
   • Switch
     • Connect various devices simultaneously and it works in the data link layer.

4. Network

   • IP addressing
     • An IP address, or Internet Protocol address, is a series of numbers that identifies any device on a network.
   • MAC addressing
     • Ensures the computer device's physical location.
   • Protocols
     • A network protocol is an established set of rules that determine how data is transmitted between different devices in the same network.
       • Management
       • Communication
       • Security

5. Compresion

   • Lossy
     • In lossy compression, the data in a file is removed and not restored to its original form after decompression.
   • Lossless
     • Lossless compression restores and rebuilds file data in its original form after the file is decompressed.

6. Secondary Storage

   • Secondary storage is non-volatile , long-term storage. It is used to keep programs and data indefinitely. Without secondary storage all programs and data would be lost the moment the computer is switched off.