Commitment
Merriam-Webster defines it as:
1. a : an act of committing to a charge or trust: as (1) : a consignment to a penal or mental institution (2) : an act of referring a matter to a legislative committee b : mittimus
2 a : an agreement or pledge to do something in the future; especially : an engagement to assume a financial obligation at a future date b : something pledged c : the state or an instance of being obligated or emotionally impelled <a commitment to a cause>
A very simple, easy to understand definition - but a difficult, hard to implement concept. Why?

