ELI5: Explain Like I'm 5

Proprietary software

Proprietary software is software that is owned by a specific company or person and only they have the rights to use it and control how it is used. This software usually has to be purchased or rented from the company instead of being downloaded. The company or person that creates the software often puts safeguards in place (like passwords and codes) to ensure that only they, or somebody they approve, can use the software.