I believe Bob can explain better, but I can try my best.
A section is where you can put your text. These are 2 sections as example:
I called my 1st section "Biography" and the 2nd one "Personal Life". The result looks like this:
You can see in this example that Bob used 3 sections to create the item for the Mustang.
1969 Boss 429
So you can have up to 5 sections like this and fill out each of them, and that way you have 5 sub-titles for each item.
However, technically speaking you don't need 5 sections. You can also achieve the same result by having only 1 section (probably meta-things aside).
If your maximum item length is long enough (the amoung of characters you can type in):
You can basically achieve the same result within the first section by writing everything in the first section. You can use font-size and blank spaces nd make it look like you have multiple sub-titles and sections.
But I find it more cleaned up and straight forward having multiple sections. It makes it easier for the user to separate things. Like "now here you have to place the biography of the person". "Here his personal life"and "here his works" etc. As said, you could ask the user to write down everything in the first section, but I like it more this way as it also includes automatically sub-titles. Not sure why we should be limited to only having 5 sections.
Btw. we don't need to have 5 sections. By default 1st section is activated. You can configure if you want more sections than one. I activated the first 2 in my example above.
And in case in future Bob implements a "table of contents", he can automatically parse the titles from each section which would make it easier for him I think.
Hope it explains it.