The word "Avatar" can have more meanings: it could be a film title, an user image on a forum and a lot of other things. We can understund what we're talking about using the context, a machine can't, it needs more information.
For this reason schema.org dictionary was created: adding its elements we can define if a man is a director movie, the length of a video or how many comments an item received.
Adding these tags won't make you climb position, but you'll have much more: your results will become nicer than simple links since they will be transformed in "rich snippets".
J4Schema is a visual editor for schema.org attributes: you can add them quickly to your pages, you only have to select the text you want to "enrich" and you can start adding attributes.
Easily navigate and inspect all the attributes with our GUI
All Schema.org attributes listed in one place
Check your microdata easily with our module
Ready to use templates for Virtuemart with microdata
Ready to use templates for K2 with microdata