Development
The development section has a number of screens and settings that are most useful when you are building your website and less so once it is live. The settings here are often different between development and going into production. Some of these settings will be changed just before a site goes into production.
Performance
The performance settings page has two subsections that perform distinctly different functions.
Caching
For anonymous visitors to your website, it's very common for each visit to a specific page to return the same generated HTML.
Depending on the complexity of the page, Drupal will have to make many calls to the database to collect all of the data it needs to assemble the page view. If the page is always the same, it is wasted effort to reassemble it every time someone requests the page. Therefore, we can specify that the generated page output is cached for a certain period of time.
This means that subsequent visitors to the same page will receive it more quickly and...