When a custom virtual background is unavailable or not suiting your needs, but you still want to maintain some privacy with regards to your surroundings, the blur background option can be a great alternative. This option simply blurs the background of your video, obscuring exactly who or what is behind you. It's great for hiding a cluttered dorm room, taking a meeting in a coffee shop, or just keeping things professional.
Zoom desktop client:
Windows: 5.5.0 (12454.0131) or higher
macOS: 5.5.0 (12467.0131) or higher
The Blur option is just a variant of the virtual background options, and is directly controlled by the Virtual Background setting. Please refer to the Zoom - Virtual Backgrounds