What distinguishes open source software from proprietary software?

Open source lets you see, change, and share the code freely. Proprietary software keeps the code secret and restricts what you can do. This freedom to modify is the key difference, not just price.

Some open source costs money, and some proprietary software is free. Security depends on implementation, not the license type. Both individuals and corporations develop both types of software.

Open source encourages collaboration and transparency. Anyone can improve the code and share their improvements with others.