You're welcome. Check your computer documentation, it may give you a lot of
information. Or, you can look for the make and model of your PC on the
Internet, just type the manufacturer and model of your system into a Google
search box,
www.google.com and press enter. If your computer is for sale at
some site, probably many sites, the site may also have the pertinent
information or visit your PC manufacturer's website as they should have the
specs.
A graphics card essentially allows your system to display graphics, that's
anything you see on the monitor. There are many different types of cards
and memory configurations as some are built in while others are add-in and
for more intense graphics including the playing of DVD movies, it's best to
have an add-on with plenty of its own memory.