They are synergetic they are more than the sum of their parts. A forest program requires that someone spend money on something from which they don't get a return it requires involuntary sacrifice by someone. A forest protecting system requires no sacrifice only tradeoffs. Programs are reactive they happen after the fact. Systems are preventive.
Programs are usually divisible.
Systems are not. A program divided in half is about half as useful as it otherwise would have been. A system divided in half is fundamentally different, and far less useful than as a distinct whole. Programs operate within systems. Systems are catalysts and enablers to programs.