To elaborate: open source means that anyone can download the enire source code for that software, inspect, make changes to the code, and build your own version.
This literally means that anyone 'owns' the software when they download it. And anyone is allowed to release their own version
The software is 'owned' by the community.
For example, an ex-TrueSpace user who disagreed with Blender's user interface direction decided to release his own customized version of Blender called "BlenderForArtists".
It also means that all older versions remain available in perpetuity.
I have Blender 2.79 running on my Raspberry PI
@buttongerald Blender is an amazing piece of software and indeed unbelievable for the price.
Other professional level open source apps are:
Krita -- brilliant digital painting software, outperforming many commercial offerings
OpenToonz -- production level animation studio software. Used for feature length traditional 2d animation.
Storyboarder -- excellent professional storyboarding software (current version has some issues with its 3d shot generator on M1/2 macs)
Godot -- high level game development authoring environment, comparable to Unity / GameMaker Studio
Firefox -- well-known browser
LibreOffixe -- capable MS Office alternative
Visual Studio Code -- super popular coding environment
Open Broadcast Studio -- high level recording and streaming software
...and many more. And let's not forget
Linux -- free operating system (many variants).