Compact Crank vs. Standard
If you want to be a good climber, go with compact. All the best climbers in the world use compact cranks, and it is especially recommended when the road gets steep and the cadence is dropped.
Compact crank refers to the size of the chainrings. On this dura ace 9000 compact crank, the outside is a 50 teeth chainring and the inside a 34. With the dura ace, you can switch between compact and standard cranks without having to remove the crank arm. On the Sram Red crankset it is the same, the big chainring has 50 and the smaller with 34. Lastly is a standard crankset, it has 53 teeth on the outside and 39 on the inside, so it is quite fast on flat surfaces. When climbing though, compact cranks will help you maintain a high cadence and be able to maintain good spinning motion while going uphill.
Breaking it all down, for the majority of cyclists out there, a compact crankset is going to be the best choice for you, unless all of your riding is at 35 km per hour, in which case a standard crankset will be ideal. Being all about cadence and maximum watts per kilo, a compact crankset will stop you from being bogged down when you hit more difficult angles. If you are an extremely fast sprinter, standard is the way to go.