Open source is defined as software and products with source code that is freely available for anyone to study, modify, and redistribute. It typically refers to software that is released under an open source license, in which the copyright holder grants users the right to study, modify, and redistribute the software free of charge. Open source projects are often developed collaboratively by multiple users.

Open source software is often seen as a way of delivering software quickly and cheaply, giving developers an alternative to expensive and slow-moving closed-source solutions. By working together, these developers can pool resources and create innovative solutions to their problems without having to pay for costly licenses to use the software.

Open source software is often credited for the creation of many of today's most-used programs and operating systems. Android, Ubuntu, and Firefox are all open source projects and have become household names throughout the world. Other open source projects such as Java, WordPress and OpenOffice are also used by millions of people every day.

Open source is based around the idea of trust, collaboration, and permissive licensing strategies. Trust is important in open source projects because the code is available to anyone who wants to modify it, and the development process can be much faster than in closed-source approaches. Collaboration is essential to open source projects, allowing developers to share ideas, solutions and bug fixes quickly, across the globe. Permissive licenses also allow users to freely distribute and alter open source software without having to worry about copyright infringement or having to pay for licenses.

Open source has become an increasingly popular option for software and IT development with many organizations choosing to use open source products and solutions instead of closed-source options. By using open source software, projects can benefit from low-cost solutions and high levels of customization. Open source also fosters innovation and encourages ideas from the global community of developers working on the same project.