SOFTWARE ENGINEERING

Detailed explanation-1: -Proprietary software can be distributed at no cost or for a fee, and free software can be distributed at no cost or for a fee. The difference is that whether proprietary software can be distributed, and what the fee would be, is at the proprietor’s discretion.

Detailed explanation-2: -Non-free software is any software that is not free. This includes semi-free software and proprietary software. Semi-free software is software that is not free, but comes with permission for individuals to use, copy, distribute, and modify (including distribution of modified versions) for non-profit purposes.

Detailed explanation-3: -Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions.

Detailed explanation-4: -With closed source software (also known as proprietary software), the public is not given access to the source code, so they can’t see or modify it in any way.