You must have the Manage Lists permission level to create columns for lists or libraries. Specify whether you want the term set to be Closed or Open.
If a term set is closed, then users cannot add new terms to it when they are updating the value for a Managed Metadata column bound to this term set, and the term set can be updated only by individuals with permission to update managed metadata.
A Managed Metadata column is a new column type that can be added to lists, libraries, or content types to enable site users to select values from a specific term set of managed terms and apply these values to their content.
You can create and configure a Managed Metadata column to map to an existing term set or term, or you can create a new term set specifically for a Managed Metadata column.
Because this term set is updated and managed separately from the column itself, there is no need to update the column (or any content types, lists, or libraries associated with it) to make updated terms available to users.
Whenever the term set that a specific Managed Metadata column is bound to is updated, the updated terms will automatically become available to users wherever that Managed Metadata column is available.
Every instance stores its metadata on a metadata server.
You can query this metadata server programmatically, from within the instance and from the Compute Engine API, for information about the instance, such as the instance's host name, instance ID, startup and shutdown scripts, custom metadata, and service account information.
Or they may simply have the option to send feedback to the designated contact for the term set.
For example, you can write a startup script that gets the metadata key/value pair for an instance's external IP and use that IP in your script to set up a database.
Since the default metadata keys are the same on every instance, you can reuse your script without having to update it for each instance.
Your instance automatically has access to the metadata server API without any additional authorization.
The metadata server is particularly useful when used in combination with startup and shutdown scripts because you can use the metadata server to programmatically get unique information about an instance, without additional authorization.