rack / wrack are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
rack: (noun) framework for holding objects. (noun) rib section of a forequarter of veal or pork or especially lamb or mutton. (noun) an instrument of torture that stretches or disjoints or mutilates victims. (noun) a support for displaying various articles. (noun) a form of torture in which pain is inflicted by stretching the body. (noun) a rapid gait of a horse in which each foot strikes the ground separately. (verb) stretch to the limits. (verb) put on a rack and pinion. (verb) fly in high wind. (verb) draw off from the lees. (verb) work on a rack. (verb) seize together, as of parallel ropes of a tackle in order to prevent running through the block. (verb) torture on the rack.
wrack: (noun) dried seaweed especially that cast ashore. (noun) the destruction or collapse of something.
rack: r·AE·k
wrack: r·AE·k
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)