Magnolia 5.5 reached end of life on November 15, 2019. This branch is no longer supported, see End-of-life policy.
Magnolia does not cache personalized content by default (CE, EE Std). But you can cache it with the high performance caching modules in Enterprise Pro. These modules let you cache page variants and fragments of pages. You can configure which parts of a page are cached. Use high performance caching when your site has a lot of dynamic and personalized content.