This screen will allow you to manage cache settings for different internal Magento aspects. To access the Cache Management screen (System > Cache Management)
In this fieldset you are presented with checkboxes, which, if checked, will enable cache for each aspect as described below.
During developing, i.e. changing files or database directly, disable all cache to avoid undefined behaviour.
After extension upgrade, installation or uninstallation, refresh all cache.
During moving Magento to another server, cached config.xml and local.xml are causing problems and have effectively locked you out of the admin panel. Find /app/etc/use_cache.ser and rename it to kill all caching manually and force reload of these files.
This select box is a convenience feature to apply an action to all checkboxes.
No Change - No action will be taken that will affect all aspects.
Refresh - All cache will be cleaned, but all enabled aspects will remain enabled.
Disable - Disable all cache.
Enable - Enable all cache.
All configuration is kept in XML files and database table core_config_data. Data from these files and table is collected, merged and saved in the cache.
app/etc/config.xml - default core configuration
app/etc/local.xml - local database connection configuration, saved during Magento install wizard.
app/etc/distro.xml - used when local.xml is not available (during first steps of installation wizard)
app/etc/modules/*.xml - modules declarations
app/code/<codePool>/<namespace>/<module>/etc/config.xml - module configuration
Layouts are XML instructions of blocks combinations.
Blocks HTML Output
Caches HTML output from blocks.
Note: dynamic data generated in block classes will be cached too.
Translations are collected and merged from locale files and core_translate database table.
PEAR Channels and Packages
This feature is presently not in use since introduction of MagentoConnect Manager.
If enabled, Magento internal object collections will be cached according to specific cache id logic for each collection.
Disable during development.
In this section, checkboxes are used not to enable, but to refresh cache contents.
Refresh Catalog Rewrites
Re-generates SEO friendly URLs for catalog links (products and categories)
Clear Images Cache
cleans auto-generated resized and watermarked catalog images.
Refresh Layered Navigation Indices
Re-generates index for catalog layered navigation.