[What's the difference? Manage listings vs. Viewer-Managed Marketplace]

Thank you both very much for your help in replying - much appreciated!

[What's the difference? Manage listings vs. Viewer-Managed Marketplace]

Hello,

I'm new to the Marketplace and have been working on putting something up for sale. After I've created the listing and I go to Merhcnat Home -> Manage listings, I see my item appearing in the "Viewer-Managed Marketplace" section while the "Manage listings" section appears empty. Would anyone be willing to help me understand the difference, please?