"z=0" galaxies

For a class I'm in, our team is supposed to "Characterize the
star formation history of z=0 satellite and central galaxies."

However, I'm not sure what the term "z=0 galaxy" means. To me,
"z=0" means "zero redshift", or "right here". Since the only
galaxy that's "right here" is the Milky Way, this obviously
demonstrates some mis-understanding on my part.

Some searching has revealed stuff such as this Arxiv paper:
https://arxiv.org/pdf/1502.07747.pdf, which discusses some
attributes of "z=0 galaxies". However, it appears to be aimed
(as one would expect) at people who are already familiar with
some aspects of "z=0 galaxies".

Any suggestions on where I could find out what they are? Or, if
it's trivial to explain, would somebody please tell me?

Thanks,
--
Michael F. Stemper
Always use apostrophe's and "quotation marks" properly.