THIS CASEBOOK contains a selection of U. S. Court of Appeals decisions that analyze and discuss issues surrounding patent claim construction. * * * The purpose of claim construction is to give claim terms the meaning understood by a person of ordinary skill in the art at the time of invention. Phillips v. AWH Corp., 415 F.3d 1303, 1312-14 (Fed. Cir. 2005) (en banc). "There is a heavy presumption that claim terms are to be given their ordinary and customary meaning." Aventis Pharm. Inc. v. Amino Chems. Ltd., 715 F.3d 1363, 1373 (Fed. Cir. 2013). "Properly viewed, the 'ordinary meaning' of a claim term is its meaning to the ordinary artisan after reading the entire patent." Phillips, 415 F.3d at 1321. A patent's prosecution history, though generally "'less useful for claim construction purposes' than the claim language and written description, plays various roles in resolving uncertainties about claim scope." SAS Inst., Inc. v. ComplementSoft, LLC, 825 F.3d 1341, 1349 (Fed. Cir. 2016) (quoting Phillips, 415 F.3d at 1317). We have recognized that "the prosecution history can often inform the meaning of the claim language by demonstrating how the inventor understood the invention." Phillips, 415 F.3d at 1317.Aylus Networks, Inc. v. Apple Inc., 856 F. 3d 1353 (Fed. Cir. 2017)