$caching

This tells Smarty whether or not to cache the output of the templates to the $cache_dir. By default this is set to 0, or disabled. If your templates generate redundant content, it is advisable to turn on $caching. This will result in significant performance gains. You can also have multiple caches for the same template. A value of 1 or 2 enables caching. 1 tells Smarty to use the current $cache_lifetime variable to determine if the cache has expired. A value of 2 tells Smarty to use the $cache_lifetime value at the time the cache was generated. This way you can set the $cache_lifetime just before fetching the template to have granular control over when that particular cache expires. See also is_cached().

If $compile_check is enabled, the cached content will be regenerated if any of the templates or config files that are part of this cache are changed. If $force_compile is enabled, the cached content will always be regenerated.