If you don't know what "Premier Associate" is then N334AA's table probably won't be much help.

Try the first link on the FAQ sticky: http://www.flyertalk.com/forum/showthread.php?t=530635

This gives a brief overview:
Mileage Plus Status levels and terms in generally ascending order:
GM: General Member - No status. Just collects small amounts of miles (by FT standards, of course)
3P: Premier Associate - Unknown criteria as of yet
2P: Premier - 25000 miles or 30 segments in a calendar year
1P: Premier Executive - 50,000 miles or 60 segments in a calendar year
1K: Premier Exec 100,000 Mile Fliers - 100,000 miles or 100 segments in a calendar year

Further down the FAQ sticky, after all the links, is a more detailed description of the levels and benefits:

Mileage Plus Premier Associate

[Also known as 3P] is the newest lowest elite tier. You can only become 3P through invitation of another Elite member or through a "soft landing". Your status is valid till the last day in February of the year following your appointment.

Benefits include:
Star Alliance Silver status.
36 Hour Upgrade Window when using 500 mile certificates or Y/B fare complimentary upgrade.
Discounted price when purchasing 500-Mile upgrades [$200 for four vs. $325].
Allowed to pre-book Economy Plus seating on UA flights.
Zone 1 Boarding Priority when flying in Economy on UA flights.
Priority boarding when flying in Economy on Star Alliance flights.
Priority check-in with UA and Star Alliance airlines.
Priority upgrade waitlist when there are no available upgrade seats on a UA flight.
Priority reservations waitlist when the flight or eligible fare you want on any Star Alliance member airline is sold out.
Priority standby at the airport (where allowed by law) for any Star Alliance flight if you are traveling without a confirmed reservation.
Discounted rate on United Red Carpet Club memberships [$400 vs. $500].
Access to a private, toll-free domestic reservations number.

Or, you could always do a search....