Other forms: praxes; praxises
Use the noun praxis when you talk formally about putting an idea or theory into practice. You might have a lot of theories and opinions about raising kids, but it's much harder in praxis, when you have kids of your own.
Praxis comes from the Greek word prattein, which means "to do." Aside from having the meaning of putting an idea into action, praxis also means "an established custom or practice." Your mom may have chosen a particular school for you because of its common praxis of parents helping out in the classroom.