What are they talking about?

http://www.anandtech.com/mb/showdo [...] =2797&p=19

[]The Value DDR2 tests comparing seven 2GB DDR2 kits at less than $200 provided quite a few surprises. ALL of the seven brands reached DDR2-800 with a voltage increase to around 2.2V. This performance was a complete surprise for DDR2 memory kits rated at DDR-533 or DDR2-667. Most of the value kits also reached DDR2-800 memory timings of 4-3-3. This is only slightly slower than our High-Performance DDR2 group at DDR2-800 3-3-3. This means performance of this group is almost exactly the same at DDR2-800 or DDR2-667 as the High-Performance DDR2 - at less than half the price! We will have additional Conroe performance test results from this group in a future article.[]

Are they talking about overclocking the 533 and 667 to 800? I know squat about RAM. If not OCing than what does all this mean in layman's terms?