Review: applications and software

Domain 3, applications and software, covers the layer that most people mean when they say "the computer": the operating system, the files and folders, the programs they open every day, and the web browser where much of their work now happens. It is worth roughly 18 in every 100 points, about thirteen questions. Noor rated herself 4 on it because she spent years helping patrons with browsers, printing and word processors. Lorna agrees that she knows the practical side well, and so she wants this review to sharpen the vocabulary around it: the names of operating system functions, the categories of software licence, the exact meaning of browser features, and the newer objective on artificial intelligence, which COMP-110 lesson 9 introduced and which is easy to underestimate.

What domain 3 covers

The domain has five main areas. The first is operating systems: what they do, their main components, and the differences between desktop, mobile, server and embedded systems. The second is file management: file types and extensions, paths, folders, and basic permissions. The third is applications: common types, licensing models, and how software is installed, updated and removed. The fourth is the web browser: settings, features, security indicators and troubleshooting. The fifth is common uses of artificial intelligence, including generative AI, and its limits. Each area tends to produce questions that ask you to identify, compare or choose.

Operating systems

An operating system manages the hardware and provides services to applications and users. Its main functions are managing processes (deciding which program runs on the processor and when), managing memory, managing storage through a file system, managing devices through drivers, providing a user interface, and enforcing security through accounts and permissions. Questions often describe one of these jobs and ask which OS function it is. A program that has stopped responding is handled by process management; a printer that appears after its driver is installed is device management; a user who cannot open another user's files is being stopped by access control.

Operating systems fall into families. Desktop systems include Windows, macOS, Linux distributions and ChromeOS. Mobile systems include Android and iOS (and iPadOS on tablets), designed for touch, sensors and long battery life, with apps installed mainly from app stores. Server operating systems, such as Windows Server and server editions of Linux, are built to provide services to many users and to run without a person at the console. Embedded operating systems run inside devices such as routers, printers and kiosks and are usually updated as firmware. A useful exam clue: if the scenario mentions an app store, touch and battery, think mobile; if it mentions many users connecting to a service, think server.

Files, folders and extensions

File management questions test paths, extensions and basic housekeeping. A path describes where a file lives. On Windows, a path such as C:\Users\Noor\Documents\plan.docx starts with a drive letter and uses backslashes; on macOS and Linux, a path such as /home/noor/plan.txt starts at the root, written as a forward slash, and uses forward slashes. An extension, the letters after the last dot in a file name, tells the operating system which application should open the file. Common ones include .docx for word processing documents, .xlsx for spreadsheets, .pptx for presentations, .pdf for portable documents, .txt for plain text, .jpg and .png for images, .mp3 for audio, .mp4 for video, .zip for compressed archives and .exe for Windows programs.

Extensions are also a security topic. Windows hides known extensions by default, which lets a malicious file named invoice.pdf.exe appear as invoice.pdf. Showing extensions is a simple, worthwhile setting on staff computers. Compressed archives such as .zip files reduce size and bundle many files together, which is useful for email attachments and backups. Permissions control who may read, change or run a file; on a shared computer they keep one user's files private from another.

Applications and licensing

Application types appear in scenarios. Productivity software includes word processors, spreadsheets and presentation tools. Collaboration software includes email, calendars, chat, video conferencing and shared document editing. Business software includes accounting, customer relationship management and specialized systems such as the library's integrated library system. Utility software maintains the system: backup tools, antivirus, compression tools and disk cleaners. Applications can be installed locally, run in a web browser, or delivered from the cloud as a subscription, and many are offered as all three.

Licensing questions are reliable points if the terms are clear. Proprietary software is owned by a company and used under its licence terms; the source code is not shared. Open-source software publishes its source code under a licence that allows people to study, change and share it, although some open-source licences add conditions about how changes are shared. Freeware is free to use but not necessarily open source, and its licence may restrict commercial or organizational use. Shareware or trial software can be tried before buying. A single-use licence covers one installation or one person; a group or volume licence covers a set number; a site licence covers an entire organization or location. A subscription licence must be paid periodically and stops working if payments stop; a perpetual licence is paid once. The exam favourite: free to download does not mean free to use anywhere. Read the licence.

Installing software safely means checking system requirements, obtaining it from a trusted source (the publisher, an official app store, the organization's software portal or a package manager), having the right permissions to install it, and keeping it updated. Removing software should be done through the operating system's uninstall feature or the package manager, which removes services, shortcuts and settings that deleting a folder would leave behind.

Updates deserve their own attention on the exam. Operating system and application updates fix security vulnerabilities and bugs and sometimes add features. Automatic updates keep most home devices current with no effort, while organizations often test updates on a small group of computers before rolling them out to everyone, so that a faulty update does not stop the whole library at once. A patch that fixes a security problem should be applied promptly; a major upgrade that changes how a program works may be scheduled for a quiet period, with users told in advance. Software that no longer receives security updates from its maker, often called end-of-life software, should be upgraded or replaced, because every new vulnerability discovered in it stays open forever.

Mobile devices add one more layer: app permissions. When an app asks to use the camera, microphone, location, contacts or photos, the operating system asks the user to allow or deny it, and the setting can be changed later. Good practice is to grant only the permissions an app needs for what it does. A torch app has no reason to read contacts. On devices the organization owns, mobile device management can push approved apps, block others and enforce settings, which is how the library manages its lending hotspots and staff tablets.

Web browsers

Browser questions test features and their privacy and security effects. The cache stores copies of web content to speed up later visits; clearing it can fix pages that display outdated or broken content. Cookies are small pieces of data that websites store in the browser, used for staying signed in, remembering preferences and tracking; clearing them signs the user out of sites. Private or incognito browsing does not save history, cookies or form data after the window closes, but it does not hide activity from the network, the employer or the website itself. Extensions and plug-ins add features but can also collect data or carry malware, so they should be installed only from trusted sources and kept to a minimum. Pop-up blockers stop unwanted windows. A proxy setting sends browser traffic through another server, often in organizations.

Security indicators include HTTPS and certificates. HTTPS means the connection between the browser and the website is encrypted and the site has presented a certificate showing that it controls the domain name. It does not mean the site is honest; criminals can obtain certificates for look-alike domains. A certificate warning means something is wrong: the certificate may have expired, may be for a different name, or the computer's date and time may be wrong, which is the first thing to check if every site shows a warning on one computer. Reading the domain name carefully, especially the part just before the first single slash, is the best defence against fake sites.

Artificial intelligence

The Tech+ objectives include common uses of artificial intelligence. Candidates should recognize everyday examples: recommendation systems that suggest books or videos, voice assistants that understand spoken requests, image recognition that sorts photos, spam filters, translation tools, and generative AI tools that produce text, images or code from a prompt. Large language models are the kind of generative AI behind chat assistants. The exam also expects awareness of their limits and risks. Generative AI can produce confident but incorrect output, often called hallucination, so its answers must be checked. Information typed into a public AI tool may be stored or used by the provider, so personal or confidential data should not be entered without approval. AI output can reflect bias in its training data. And organizations should have a policy saying which tools may be used for what.

Lorna connects this to something the library actually did. When the teen volunteers asked for an AI assistant in the makerspace, Hana reviewed the tool's data handling and the library set rules: no patron data in prompts, every output checked before use, and a notice explaining what the tool is. Those three rules map neatly onto the exam's concerns about accuracy, privacy and transparency, and Noor uses them as her memory aid.