What Is Open Source Software?

Open source software is software whose source code is made available under a license that allows people to inspect it and, depending on the license, use, modify, and share it. The short version is that the code is open for others to examine rather than kept entirely closed.

Why That Matters

When source code is available, developers can learn from it, improve it, fix bugs, or build on it. That openness often leads to strong communities, faster feedback, and broad adoption.

It also means users and organizations are not always locked into a single vendor in the same way they might be with proprietary tools.

Open Source Does Not Always Mean Free

Many open source tools are free to use, but “open source” and “free of charge” are not the same thing. Some open source companies charge for hosting, support, enterprise features, or managed services around the software.

The license and business model are separate questions.

Can Open Source Be More Secure?

Sometimes, yes, because more people can inspect the code and report issues. But open code does not guarantee secure code. Security still depends on maintenance, responsiveness, and how the software is actually used.

An abandoned open source project can be riskier than a well-maintained closed one.

Summary

Open source software is software whose code can be inspected and often modified or shared. It offers transparency and flexibility, but it still needs maintenance and trust. For related basics, see What Is Git? and What Is an API?.