Globalization and localization enable your Web API to support multiple cultures, languages, and regions. In ASP.NET Core Web API, you can implement globalization and localization by using the Localization middleware and resource files. The Localization middleware sets the current culture and UI culture based on the client's preferences or the request headers. Resource files, organized by culture, contain localized strings for different languages. You can retrieve the localized strings in your API code using the IStringLocalizer interface. Implementing globalization and localization allows your Web API to provide multilingual responses and adapt to different cultural conventions.