Memcache setup page allows to enable/disable the memcache setting. As the page states, enabling memcache for production sites will boost the performance and reduce access times. If memcache is enabled for development, it could happen that changes performed to the page are not seen because and old version is cached, thus the recommendation of disabling memcache for dev environments.
Don't forget to enable related modules (follow the link in the page), and don't forget to set the configuration for the module. Go to the performance configuration page:
If you notice that an updated content is being presented as the old version, or you notice inconsistencies, you may come to this page and clear the caches.