Weaknesses Flashcards
What is utility software?
Software designed to maintain or optimise a computer system, e.g. antivirus, backup, defragmentation.
What does disk defragmentation do?
It rearranges fragmented data on a hard disk to improve read/write speed.
Why is disk defragmentation not useful for SSDs?
SSDs have no moving parts; defragging reduces their lifespan and gives no speed boost.
Give two types of backup and how they differ.
Full backup (everything) vs Incremental (only changes since last backup).
What does compression software do?
Reduces file size to save storage or speed up transfer (e.g. ZIP files).
How many bits in a nibble?
4 bits.
How many colours can 8-bit colour depth store?
2⁸ = 256 colours.
How do you calculate file size for a bitmap image?
Width × Height × Colour depth (in bits).
What is the difference between lossy and lossless compression?
Lossy = data lost (JPEG); Lossless = no data lost (PNG, ZIP).
Why is Unicode used instead of ASCII?
Supports more characters (e.g. for different languages).
What are the three types of secondary storage?
Optical (CD), Magnetic (HDD), Solid-state (SSD).
Advantage of SSD over HDD?
Faster, quieter, more durable (no moving parts).
Disadvantage of optical storage?
Low capacity, easily damaged.
Which storage is best for backing up large files regularly? Why?
Magnetic HDD – cheap, high capacity, reliable.
What does volatile mean in storage?
Loses data when power is off (e.g. RAM).
What is the difference between LAN and WAN?
LAN = local (home/school); WAN = wide area (Internet).
Why use a star topology over bus?
Faster and easier to isolate faults; but more cabling needed.
What is a protocol?
A set of rules for communication (e.g. HTTP, TCP/IP).
Why is HTTPS better than HTTP?
HTTPS encrypts data; HTTP does not.
What does a switch do?
Connects devices on a LAN and sends data only to the correct device.
Difference between a variable and a constant?
Variable can change; constant stays the same during program execution.
What is the purpose of a loop?
Repeats a block of code (e.g. FOR, WHILE).
What is the difference between syntax and logic errors?
Syntax = code rules broken; Logic = code runs but wrong result.
What does an IDE provide to help programmers?
Code editor, error detection, debugger, translator.
What is defensive design?
Anticipating misuse – e.g. input validation, authentication.
What does SQL stand for?
Structured Query Language.
Write an SQL query to select all data from a table called ‘Students’.
SELECT * FROM Students;
How do you search for students aged 16 in SQL?
SELECT * FROM Students WHERE Age = 16;
How do you sort students by name in SQL?
SELECT * FROM Students ORDER BY Name;
How would you select only names and grades?
SELECT Name, Grade FROM Students;
What is social engineering?
Tricking people into giving up sensitive data (e.g. phishing, pretexting).
What is penetration testing?
Legally hacking into a system to find vulnerabilities.
Name two types of malware.
Virus and ransomware.
What does a firewall do?
Monitors and controls incoming/outgoing network traffic.
Why are software updates important?
Patch security vulnerabilities, fix bugs.
What are the four main parts of the CPU?
ALU, CU, Cache, Registers.
What is the fetch-decode-execute cycle?
The process of retrieving, understanding, and executing instructions.
What is clock speed?
Number of instructions a CPU can process per second (measured in GHz).
What does RAM do?
Temporary memory for programs being run.
Difference between RAM and ROM?
RAM = volatile, editable; ROM = non-volatile, stores BIOS.
What is open-source software?
Free to use and modify (e.g. Linux).
What is proprietary software?
Owned and protected – users can’t change code (e.g. Microsoft Word).
Advantage of open-source software?
Free, flexible, community support.
Disadvantage of open-source software?
May lack professional support and polish.
What’s the purpose of an operating system?
Manages hardware and software – provides user interface, memory and file management.
Give an advantage and disadvantage of cloud storage.
Adv: Accessible anywhere; Disadv: Needs internet, privacy concerns.
Why is cache memory faster than RAM?
Closer to the CPU and stores frequently used instructions.
Give one reason for using hexadecimal.
Easier to read and debug than binary.
Describe one real-life use of sensors in embedded systems.
Thermostat: uses temperature sensor to control heating.
Why is layered protocol model (like TCP/IP) useful?
Breaks communication into manageable layers – easier to troubleshoot and develop.
