High school football fields and NFL fields have the same length and breadth. Both fields are 120 yards long and 53.3 yards wide.
However, there is a difference in the hash marks. In the high school football fields, the hash marks are 53 feet and 4 inches apart, whereas, in the NFL fields, the hash marks are 18 feet and 6 inches apart.
Hash marks help referees and players recognize on-field locations and visually measure distances.
This difference in the hash marks impacts the ability of ball carriers to move around in the field. Narrower hash marks make it more difficult for offenders to move the ball down the field, whereas wider hash marks give the offensive players more flexibility.
It's much easier for defenders to cover the field and disguise more pressure in NFL than in high school football. This impacts the dynamics of the game.