Caching can greatly improve WordPress performance by saving a copy of the static files generated dynamically from PHP and the data received from the database and serving them to visitors who request for the same pages. This can be set to expire after a preset period of time or upon request. ⏱️
Object caching, page caching, and browser caching are some of the various types of caching that can be enabled on your site.
You can learn more about them from the below resources –
For example, of caching a remote request using transients, see the example in Interacting with remote data and APIs.