1. A method of classifying data, comprising: installing a first data classification agent on a single computing device, wherein— the first data classification agent is specific to only a first application associated with the single computing device, the first data classification agent identifies data generated by only the first application, including a first set of data, the data generated by the first application is stored on the single computing device, and the first data classification agent classifies the first set of data generated by the first application that is stored on the single computing device according to characteristics of the first set of data; automatically classifying the first set of data by the first data classification agent installed on the single computing device to generate a first set of metadata, wherein— the first set of metadata includes one or more first classifications of the first set of data that are associated with the first set of data, the one or more first classifications contain information describing characteristics of the first set of data, and the first set of metadata includes metadata other than metadata provided by a file system of the single computing device; installing a second data classification agent on the single computing device, wherein— the second data classification agent is specific to only a second application associated with the single computing device, the second application is different from the first application, the second data classification agent identifies data generated by only the second application, including a second set of data, the data generated by the second application is stored on the single computing device and the second data classification agent classifies the second set of data generated by the second application that is stored on the single computing device according to characteristics of the second set of data; automatically classifying the second set of data by the second data classification agent installed on the single computing device to generate a second set of metadata, wherein— the second set of metadata includes one or more second classifications of the second set of data that are associated with the second set of data, the one or more second classifications contain information describing characteristics of the second set of data, and the second set of metadata includes metadata other than metadata provided by a file system of the single computing device; populating a metabase with the first and second sets of metadata; and performing a data management operation on a subset of the first and second sets of data based on a subset of the first and second classifications included in the metadata in the metabase.