As window covers, they are synonymous: Drape : hanging cloth used as a blind (especially for a window) Curtain : hanging cloth used as a blind (especially for a window) The differences, I think, are more personal than definitive. I myself picture curtains as having the possibility of being sheer (though others are translucent and covered with ugly floral motifs), while drapes to me must be heavy, opaque and preferably of velvet.
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