I’m going to put this simply to start off with, then I’ll go a bit more technical. Giclee for dummies: A giclee is a print that is done usually on canvas or watercolor paper with a high quality ink that should look a lot like the original art work. Example: You paint an oil painting on canvas, the giclee is then printed on canvas and looks almost like a real painting, when really it’s just a print.
Now for the technical answer. Per Wikipedia:
The word “giclée,” as a fine art term, has come to be associated with prints using fade-resistant, archival inks (pigment based, as well as newer solvent based inks), and archival substrates primarily produced on Epson and some other types of large format printers… A wide variety of substrates are available including various textures and finishes such as matte photo paper, watercolor paper, cotton canvas, or artist textured vinyl.
Giclees are more expensive to have made, and you can also sell it for more. I’ve shopped around and a 16×20 giclee would cost you in between $60-$80.