What is the difference between an application (app) and an operating system?

The OS manages hardware and provides core services; apps are programs that run on top of the OS to perform specific tasks for users Apps are made by companies; operating systems are made by governments The OS is stored on the internet; apps are stored locally on the device Apps are faster than the OS because they are smaller programs

What is 'source code'?

The human-readable text that a programmer writes, which is later converted into instructions a computer can run The binary code stored inside the computer's CPU The original idea for a program written in plain English before coding begins Secret code used by programmers to communicate with each other

What is the software development lifecycle (SDLC)?

The structured process for planning, creating, testing, deploying, and maintaining software How long a software program runs before needing to be replaced The period between when a programmer starts and finishes typing code The legal process for getting a software copyright

What is open-source software?

Software whose source code is publicly available — anyone can read, modify, and often redistribute it Software that is always free to download and use Software that works on any operating system without modification Software that has no copy protection and can be installed on unlimited devices

Why do software companies release 'updates' and 'patches' after a program is released?

To fix bugs, close security vulnerabilities, improve performance, and add new features discovered or requested after release Because companies intentionally release buggy software to make users pay for fixes Updates are only cosmetic changes to the interface — they don't affect functionality Updates are only required for free software — paid software is always complete

What is a 'compiler' and how does it differ from an 'interpreter'?

A compiler translates an entire program to machine code before running it; an interpreter translates and executes code line-by-line at runtime A compiler is used for large programs; an interpreter is used for small scripts A compiler checks for grammar errors only; an interpreter actually runs the code They are the same thing — different words for the same tool

What does 'version control' (like Git) do for software development?

It tracks every change made to code over time, allowing teams to collaborate and revert to any previous version if something breaks It assigns version numbers to finished software for legal and sales purposes It prevents other developers from editing code you're currently working on It automatically tests code and rejects changes that introduce bugs

What is 'agile' software development?

An iterative approach where software is built in short cycles, with frequent user feedback and adjustments throughout A method where programmers write code as fast as possible without planning Software built for mobile devices that needs to be lightweight and fast A competition format where teams race to build software in 24 hours

What is a 'software bug'? Where does the term come from?

An error in code causing unexpected behavior — the term comes from 1947 when an actual moth was found causing a relay failure in a Harvard computer Malware that infects software like a biological virus — named after actual viruses A feature that wasn't finished before release — named because it 'bugs' the users Code deliberately hidden in software by hackers — they hide like bugs under rocks

What is the purpose of 'testing' in software development?

To verify the software does what it's supposed to do and find bugs before users encounter them To measure how fast the software runs on the latest hardware To market the software to potential customers before release To get government certification that the software meets legal standards