Page Cache — If you use a CMS, such as WordPress, whenever a page is viewed the server has first to query the database and run scripts to understand what form it should take. Page Caching stores a copy of the finished page so it can be retrieved without having first to do all this work for subsequent loads.
Database Cache — This stores the results of any database queries, making the retrieval of subsequent duplicate queries faster.
Fragment Cache — A page can be made up of various parts (i.e. Main content, Sidebar, Footer, etc.). Fragment Cache works like Page Cache but can store and retrieve each section separately.
Object Cache — This stores any calculations made by the WordPress API into the cache.
Browser Cache — This places a copy of the webpage in the Users Browser Cache. When that user re-visits the same page using the same browser, it will be loaded from the cache stored on their computer rather than querying the web server.