What is Open Source?

"Open Source" is a term referring to something publicly accessible for people to modify and use it. Its original context was used in software programming to explain open-source software. According to the wikipedia, "Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code,^[1] design documents,^[2] or content of the product".
Advantages of open-source software include promoting collaborative participation, peer review programming, cost-effectiveness, transparency, and building communities. Examples of open source softwares: GNU/Linux, Mozilla Firefox, VLC media player, Galaxy project.

Open Source Software: Basics

In line with the Open Source Initiative (OSI), common components of an Open Source software;

• It's stored in a public repository and shared publicly. 
• It has a well-documented README file to explain what the software does.
• A contributing guide is available to guide people on how to contribute to the repository.
• It has a distribution license e.g MIT License.
• Well-defined issues in the software to help contributors fix bugs.