Any good dictionary will tell you this:
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relief
6 [French, from Middle French, from Italian rilievo relievo] a : a mode
of sculpture in which forms and figures are distinguished from a
surrounding plane surface b : sculpture or a sculptural form executed
in this mode c : projecting detail, ornament, or figures
7 a : sharpness of outline due to contrast <a
roof in bold relief against the sky> b : the state of being
distinguished by contrast <throws the two opinions into bold
relief>
8 : the elevations or inequalities of a land surface
http://www.m-w.com/dictionary/relief
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