Cursor parking?

[Hermann]

Hi all,
I'm new to this list. My name is Hermann, and I live in Germany. I use 
Linux for four years, almost all the time text Linux, with a 6 months 
interlude with Gnome and Orca.
Today I set up Speakup on my Ubuntu Feisty and explored it by reading teh 
users guide. I'm impressed of the program, but there's one thing I couldn't 
figure out, cursor parking.
Maybe I missed it in the guide, but what does "parking" do and in which 
cases is it useful?
Thanks for your patience with a beginner.
Regards
Hermann