1. Co-ordination at its simplest is when pieces help each other -- as when your Bishop and Knight gang up on f7 (first example), or fail to help each other, when they are pointing in different directions (also the first example).
2. When it works, you can feel the pieces 'flow' nicely on the board, having a supportive role for each other -- either attacking the same squares or making sure all the squares are covered by someone in the team. (Botvinnik-Robatsch)
3. You can decide on one set-up and find that circumstances change, so you change your set-up to be better co-ordinated. One example is the Breyer Defence to the Lopez.

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[Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "Coordination and discoordination"]
[Black "?"]
[Result "*"]
[PlyCount "12"]

1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Ng5 {White's pieces coordinate to attack f7}
d5 5. exd5 b5 6. Bxb5 Qxd5 {Black has sacrificed a pawn and looks nicely
placed, while White's pieces suddenly seem to be pointing in different directions.} *

[Event "IBM"]
[Site "Amsterdam"]
[Date "1966.08.02"]
[Round "8"]
[White "Botvinnik, M."]
[Black "Robatsch, Karl"]
[Result "1-0"]
[ECO "D36"]
[Annotator "coordination"]
[PlyCount "57"]
[EventDate "1966.07.22"]
[EventRounds "9"]
[EventCountry "NED"]

1. c4 Nf6 2. Nc3 e6 3. d4 d5 4. cxd5 exd5 5. Bg5 c6 6. e3 Be7 7. Qc2 O-O (7...
Ne4 {?} 8. Bxe7 Qxe7 9. Nxd5) 8. Bd3 Nbd7 9. Nf3 Re8 10. O-O {[#]} Nf8 (10...
h6 11. Bf4 Nh5 12. Nxd5 cxd5 13. Bc7) 11. Rae1 Ne4 (11... Be6 {was better}) 12.
Bxe7 Qxe7 13. Bxe4 dxe4 14. Nd2 {[#] Black has been allowed a stand in the
centre, but it may be only an Aunt Sally.} b6 {? too slow} (14... f5) 15. Qa4
f5 16. f3 {[#] ouch} exf3 17. Nxf3 Bb7 18. Ne5 Qe6 19. Qc2 Bc8 {[#]} 20. e4 Qd6
21. Rd1 Ne6 22. Qb3 fxe4 {[#] hoping for Nxe4, Qd5} 23. Rf7 {Stunning, but
based on a concrete lead in development and nicely posted pieces} a5 (23...
Nxd4 24. Rf8+ Kxf8 25. Qf7#) (23... Ng5 24. Nxe4) (23... Rf8 24. Rxf8+ Kxf8 25.
Nxe4 Qd5 26. Qf3+ Ke7 27. Qf7+ Kd8 28. Nc3 Qd6 29. d5) (23... e3 24. Ne4 Qd5
25. Qxe3 Nxd4 26. Nf6+ gxf6 27. Qg3+ Bg4 28. Qxg4+ Kh8 29. Qg7#) 24. Nxe4 Qd5
25. Rxg7+ Kxg7 (25... Kh8 26. Nf6 Qxb3 27. Rxh7#) 26. Qg3+ Kf8 (26... Kh8 27.
Nf7#) (26... Kh6 27. Nf7+ Kh5 28. Nf6#) 27. Rf1+ Ke7 28. Rf7+ Kd8 29. Qh4+ 1-0

[Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "Enter New Game"]
[Black "?"]
[Result "*"]
[PlyCount "20"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 d6 8. c3
O-O 9. h3 Nb8 10. d4 Nbd7 {Breyer Defence.  The Knight when it was on c6 didn't seem to have a good square to go to next, and
was in the way of the c-pawn.  Now the Knight is playing a more coordinated role, defending f6 and e5, supporting the ...c5 push or it can hop to c5 itself in case of White's d4-d5.  If nothing much happens in the centre, it can instead try its luck on b6 or g6 (via f8) } *