Teams practice plays to that side of the field. A full speed, full pad practice in gamelike conditions. This is a way to see how the offense and defense are doing. Watching the opponent and what offenses and defenses they run. Coaches prepare to play another team by scouting them either on tape or watching them play live.
Coaches use film to check on performance and to scout opponents.
Practice with all the required pads. Once the season is going along, coaches don't practice with full pads all the time. They may go two days a week. This saves on the physical condition of the players. There is usually a spring game against each other at the end of spring practice.