Creating a transparent background on a PNG
When I looking at the new Meta website from Facebook I copied the logo (this was instead of making a screen-shot and editing). The result was an image with a transparent background.

Searching for how to do this I found that I would need a tool that is beyond the capabilities of the tools that I currently have available. I could download a tool such as Photoshop and you can also use an on-line tool, as I have done below.

Below is the original image that I used on the page.

Paint and 3D Paint
Apparently you can create a transparent background using these tools.