Customization cookies store user-chosen preferences like language, region, currency, theme, font size, or accessibility settings, so the site remembers them across pages and visits. Common examples include lang, _locale, theme, and currency. Vocabulary varies: most CMPs treat customization as a sub-type of "functionality cookies," alongside "personalization cookies" (which involve broader behavioural data). Under GDPR and ePrivacy Article 5(3), customization cookies are exempt from consent if the preference was actively chosen by the user and the cookie only delivers that choice. If the preference is inferred or used for profiling, opt-in consent is required. CCPA treats them as opt-out, lower risk.