There are several different ways a log can be cut into flooring. Depending on how the long is cut will dictate what your floor will look like. Here is a brief description of each cut to help you understand what type of floor you may be looking for.
Plain sawn: One of the most commonly used milling and is an efficient milling method. The results of this milling gives the floor a cathedral grain pattern.
Quarter Sawn: This cut is produced by quartering the log, which is a more wasteful method. The results of this milling is a straight and striped grain with "ray and fleck" patterns in white and red oak. This type of milling also always the floor to be more dimensionally stable then plain sawn flooring.
Rift Sawn: This cut is one of the most rare in flooring because how wasteful it is during the milling process. This also makes it the most expensive. This cut produces a straight grain pattern, also making it more dimensionally stable then other milling methods.
Live Sawn: This type of cut displays the full range of the grain in a log from cathedral grain to quarter Sawn grain. This type of milling is also most efficient because it produces the least amount of waste.
I hope this helps you better understand each cut during the milling process and how it effects the overall look of your floor.