I think you're refering to the Bi-Annual flight review...
As a private pilot you do need a bi-annual flight review every 24 months. This means going up with a CFI for a minimum of 1hr and doing a minimum of 1 hr of ground. Keep in mind that 1hr is a minimum and that the CFI has to work with you in areas that he/she sees you as being deficient.
Don't forget to have the CFI endorse your logbook!
One way you don't have to do a bi-annual is by getting a new certificate or rating. Basically any check ride given by the FAA will count (multi-engine, instrument, commercial, CFI etc.) An endorsement (complex, high perf, tail dragger) does not count.
Hope this helps.