Linux is an open source operating system (OS) kernel originally created by Linus Torvalds in 1991, often combined with GNU tools and other software to form full distributions; it manages hardware resources, runs on a wide range of devices (servers, computers, mobiles), and serves as a free, Unix-like alternative to proprietary OSes like Windows or macOS.
"What Is Linux?" Red Hat, www.redhat.com/en/topics/linux/what-is-linux. Accessed 22 Mar. 2026.
Open source software (OSS) is software whose source code is publicly available and can be freely viewed, modified, and distributed under licenses that comply with open source principles, promoting collaboration, innovation, and community-driven development.
"What Is Open Source Software?" IBM, www.ibm.com/think/topics/open-source. Accessed 22 Mar. 2026.
Scalability refers to a system's ability to handle increased load (e.g., more users, data, or transactions) efficiently by adding resources (horizontal or vertical scaling), without major redesign, often key in cloud and enterprise software.
"What Is Scalability?" IBM, www.ibm.com/topics/scalability. Accessed 22 Mar. 2026.
Total cost of ownership (TCO) is a financial estimate that calculates the complete direct and indirect costs of acquiring, operating, maintaining, and eventually disposing of a product, system, or asset (e.g., software/hardware) over its entire lifecycle, including initial purchase, support, training, downtime, and upgrades.
"What Is Total Cost of Ownership (TCO)?" IBM, www.ibm.com/think/topics/total-cost-of-ownership. Accessed 22 Mar. 2026.
Proprietary software (closed source) is software owned by an individual or company with restricted access to its source code, where users are licensed to use it under terms that prohibit viewing, modifying, or redistributing the code without permission (e.g., via EULAs).
"Proprietary Software versus Open Source Software." American Journal of Engineering Research, vol. 2, no. 7, 2013, pp. 124-130, www.ajer.org/papers/v2(7)/O027124130.pdf. Accessed 22 Mar. 2026.
Source code is the human-readable instructions written in a programming language that define how software operates, which can be compiled or interpreted into machine-executable form; access to it enables modification and understanding of the program.
"What Is Source Code?" IBM, www.ibm.com/topics/source-code. Accessed 22 Mar. 2026.
Open standards are publicly available, royalty-free specifications developed collaboratively and consensually, allowing anyone to implement them freely to ensure interoperability, compatibility, and innovation across vendors and systems.
Corrado, Edward M. "The Importance of Open Access, Open Source, and Open Standards." 2005, pdfs.semanticscholar.org/688f/d0ca50703c042a4de87bf72e7327524aae82.pdf. Accessed 22 Mar. 2026.
Closed standards (proprietary standards) are specifications owned and controlled by a single entity or limited group, often requiring licenses, royalties, or restrictions that limit broad implementation and interoperability, favoring the controlling party.
"Proprietary vs. Open Standards." 4iPCouncil, www.4ipcouncil.com/download_file/415/774. Accessed 22 Mar. 2026.
Hosted software refers to applications installed and run on remote servers (often in the cloud) and accessed over the internet, with the provider managing infrastructure, updates, and maintenance (contrasts with locally installed software).
"What Is Hosted Software?" TechTarget, www.techtarget.com/searchcloudcomputing/definition/hosted-software. Accessed 22 Mar. 2026.
Software as a Service (SaaS) is a cloud delivery model where applications are hosted by a provider, managed entirely by them (including infrastructure and updates), and accessed by users via the internet on a subscription basis, typically through a web browser.
"What Is Software as a Service (SaaS)?" IBM, www.ibm.com/think/topics/saas. Accessed 22 Mar. 2026.
A programming language is a formal set of instructions, syntax, and rules used by developers to write source code that computers can interpret or compile to perform specific tasks or build software applications.
"What Is a Programming Language?" IBM, www.ibm.com/topics/programming-languages. Accessed 22 Mar. 2026.
A compiler is software that translates high-level source code (written in a programming language) into low-level machine code or bytecode that a computer can execute directly, performing optimizations along the way.
"What Is a Compiler?" IBM, www.ibm.com/topics/compiler. Accessed 22 Mar. 2026.
The Free Software Foundation (FSF) is a nonprofit organization founded in 1985 by Richard Stallman to promote and defend free software (as in freedom), advocating for users' rights to run, study, share, and modify software, and supporting projects like GNU.
"What Is Free Software and Why Is It So Important for Society?" Free Software Foundation, www.fsf.org/about/what-is-free-software. Accessed 22 Mar. 2026.
Open-source licensing refers to legal agreements that comply with the Open Source Definition, granting users rights to freely use, modify, and distribute software and its source code, often with conditions like attribution or share-alike requirements (e.g., MIT, GPL).
"The Open Source Definition." Open Source Initiative, opensource.org/osd. Accessed 22 Mar. 2026.
The LAMP stack is a popular open source software bundle for building and deploying web applications, consisting of Linux (OS), Apache (web server), MySQL (database), and PHP/Perl/Python (scripting language), enabling dynamic, data-driven websites.
"What Is LAMP Stack?" IBM, www.ibm.com/think/topics/lamp-stack. Accessed 22 Mar. 2026.
The Apache HTTP Server (often called Apache) is a free, open source web server software developed by the Apache Software Foundation, widely used to serve web content, handle HTTP requests, and support dynamic sites via modules.
"About the Apache HTTP Server Project." The Apache HTTP Server Project, httpd.apache.org/ABOUT_APACHE.html. Accessed 22 Mar. 2026.
MySQL is the world's most popular open source relational database management system (RDBMS), using SQL to store, manage, and retrieve structured data efficiently for web applications and other uses.
"MySQL: Understanding What It Is and How It's Used." Oracle, www.oracle.com/mysql/what-is-mysql. Accessed 22 Mar. 2026.
Community-based development is a collaborative model where software is created, improved, and maintained by a global group of volunteer contributors (individuals, companies) through shared repositories, forums, and open processes, common in open source projects.
"What Is Open Source Software?" IBM, www.ibm.com/think/topics/open-source. Accessed 22 Mar. 2026.
A support-based revenue model is a business approach (common in open source) where core software is provided free or at low cost, but revenue comes from paid services like technical support, consulting, training, customization, or enterprise editions with added features/security.
"What Is Open Source Software?" IBM, www.ibm.com/think/topics/open-source. Accessed 22 Mar. 2026.
Switching costs are the expenses (financial, time, effort, training, data migration, or relational) a user or organization incurs when changing from one product, supplier, vendor, or system to another, often creating barriers to entry for competitors.
"Switching Costs: Definition, Types, and Common Examples." Investopedia, www.investopedia.com/terms/s/switchingcosts.asp. Accessed 22 Mar. 2026.
1. A student startup is choosing an operating system for their web app servers. They want something free, customizable, and widely supported by developers. One team member suggests using Linux because it allows them to modify the system and avoid licensing fees. Which concept BEST explains why Linux fits their needs?
2. A student builds an app that suddenly goes viral on campus. Within days, thousands of new users join, and the system begins to slow down. The student upgrades the system so it can handle more users without crashing by adding more servers. Which concept BEST describes this improvement?
3. A student organization is deciding between two software options. One has a low upfront price but requires expensive maintenance, training, and upgrades over time. The other has a higher upfront cost but fewer long-term expenses. Which concept would BEST help them compare these options?
4. A student team is building a website using a LAMP stack. One member is responsible for writing the application logic using Python, while another configures the database and server. Before the website runs, their written code must be translated into a form the computer can execute. Which tool performs this translation?
5. A startup offers free open source software but charges companies for technical support, training, and custom features. Many businesses use the free version but pay for additional services as they grow. Which concept BEST describes this business model?