Easy SEF is a Search Engine Optimization extensions for Joomla! 3.x.x with which you are able to control meta infomation such as title, description, keywords, generator, robots at the front end.
All of origin meta of Joomla! will keep protected, once a new SEF was created and it's published then the plugin will crawl all of SEF data and apply them. If one of the metadata (title, keywords, description...) is empty, the plugin will apply the origin data of them.
PS: Easy SEF compatibility with any content include K2