Listings are written in a shorthand that nobody explains to you, inherited from forums that predate most of the current sites. Here is what the common terms mean.
The ones you will see everywhere
Incall. You travel to her, at premises she keeps for work.
Outcall. She travels to you, at your hotel or home. Usually carries a minimum duration. Full explanation here.
GFE. Girlfriend experience. A warmer, slower, more conversational register. Full explanation here.
PSE. Porn star experience. The more intense, performative end of the same scale. Full explanation here.
Independent. She works for herself rather than through an agency, so you are dealing with her directly at every stage.
Duo. A booking with two companions who already work together.
Overnight. Usually twelve hours or thereabouts, priced far better per hour than the same time booked in pieces.
A word of caution about all of them
None of these terms has an agreed definition and none of them is governed by anything. Two people using the same acronym can mean noticeably different things by it. Every one of them is a signal to ask a question, not an answer to one.