It has been cut against the grain.
Wooding ripping is basically a type of cutting that severs or divides a piece of wood parallel to the grain. Often with a rip saw, the rip saw works more like a series of chisels, lifting off small splinters of wood.
Rip cuts are usually made with a table saw, but other types of power saws can also be used, saws such as a band saw and radial arm saw can be used, however, at the sawmill, the head saw is the first rip-saw a wood goes through.