SNP genotyping is the measurement of genetic variations of single nucleotide polymorphisms (SNPs) between members of a species. It is a form of genotyping, which is the measurement of more general genetic variation.
On most plays, the center will snap the ball directly into the quarterback's hands. In a shotgun formation, the center snaps the ball to the quarterback lined up several yards behind him.
On offense, snaps can be taken under center, where a player stands with his hands under the center making it a handoff rather than a toss, or from the shotgun, where the center must accurately toss the ball several yards backwards.