Here are some terms which needs to be understood properly before going deep into this:
Taxonomy – A hierarchical tree of values which are centrally managed and predefined. User while putting the conent can tag the content using these taxonomy values. So If we take example of countries a taxonomy would look like:
Folksonomies: This is a set of Unmanaged set of metadata which is not centrally managed. With this user can add their own tags if they dont find a specific values defined in the managed set.
Term Store – A new database that contains taxonomies values in SharePoint 2010.
Term – A term can be defined as a node in the taxonomy. So in the example above each country is a term. Each term has an ID.
Term Sets – A collection of Terms. So it is again subset of Taxonomy.
Here is the diagram which shows how these Terms, Term Sets can be arranged in SharePoint 2010:
Tagging – Tagging is the process of applying these terms to a content item.
Managed Metadata Column: A new type of column which can be single or multi value field. This is bind to a Term Set. Multiple Managed Metadata columns can be created on a SharePoint List, Document Library or Content Type. We can make this column mandatory. When the user are tagging the content automatically SharePoint shows a hierarchial UI to tag the content.
So if we create a term set using the above example and then associate it using the Managed Metadata Column the user can select the tags easily. It shows a very intuitive interface to tag the content like:
Managed Keywords: This type of field is used for the folksonomies. With Managed Keyword users can put the new terms into the Term Store. Also Managed Keywords can be promoted as a managed Term.
Managed Keyword Column: This is also a new column and supports Managed Keywords. It is essentially a text box with lot of feature where the user can type, and they are given suggestions from the term store. If their entry doesn’t exist, the system will add it automatically in the term store.
SharePoint 2010 allows to create Terms, Term Sets and importing terms using Term Management Tool. This tool is available in Central Administration --> Manage Service Applications. A new service application with the name Managed Metadata Service is introduced to manage these operations. This services publishes these term stores and help to ensure common vocabulary for the metadata. This was partially achieved using site Columns in SharePoint 2007 which was very cumbersome and difficult to manage.
These Terms can be associated with the content using the browser, Office Clients (using Document information Panel), InfoPath forms, or by a custom application using SharePoint Object Model. SharePoint can also add this metadata based on location of the content storage which is really cool feature.
The applied Metadata help to drive search, navigation and behaviors of this content. The column headings AND left-hand navigation displays the tag taxonomy as a means of filtering or pivoting the library listing. It’s kind of automatic, faceted, dynamic folder trees based on tags which helps to browse the content easily. These terms can automatically extracted for further usages.
There is a new feature with the name Metadata Navigation and Filtering. If we activate this feature it allows to filter the data based on this metadata values.
Once we activate this feature a new link shown up in the list as shown:
See Also Document Sets in SharePoint 2010