You are welcome, Silentgypsy.
LOL! That is a wonderful question. It is basically a mushroom - the part you can see of a fungus! It is part of its reproductive system.
The implication here is that sometimes the individual “fruiting bodies” are quite small in a smaller kind of leaf fungal infection, so one would need to use a lens in order to see them clearly.
Here is what I turned up on a quick search on ‘fungal fruiting bodies’
http://www.anbg.gov.au/fungi/types-of-fungi.html
You are a total gem!!!!!