What does appreciation mean?
The definition of appreciation
Ap*pre`ci*a”tion, n.
Etym: [Cf. F. appréciation.]

1 A just valuation or estimate of merit, worth, weight, etc.; recognition of excellence.
2 Accurate perception; true estimation; as, an appreciation of the difficulties before us; an appreciation of colors. His foreboding showed his appreciation of Henry’s character. J. R. Green.
3 A rise in value; — opposed to depreciation.