This is the preamble because it comes before the first headline. This becomes a TL’DR.
preamble
This is regular preamble text that normally stops at the first headline. But one might not want to have that very first headline, so we also have the option to hide that headline and still be able to limit the preamble. This text is right before the hide attribute.
No excerpt defined!
This is the excerpt. An excerpt is just a short text without much formatting or other nifty things.