When we do a plank exercise, it is important to activate abdominal muscles in order to prevent the back from collapsing. It also work on maintaining the chest straight.
This goes according to the ceiling principle, when supporting a body hanging between two posts - your forearms and feet - requires support at its lower part - your abdominal muscles.
A front plank allows to challenge the various core muscles. There is a ton of plank variations, suitable for any level of fitness.
Our body loves variety, so be creative and try to challenge it with different plank exercises! More challenging versions involve less stability. Raise an arm, or a leg, or both, and feel how much work is now required to hole the plank position.