Data Exhaust

Relatively new term as it relates to the data lake  " ... There are no standard definitions or schemas for data exhaust, which tends to be raw and unstructured, but in many ways, it's equivalent to the byproducts associated with a company's machines and core online activities. It can include streams coming in from Web browsers, plug-ins, log files, Internet of Things (IoT) devices, and more. ... " .  A combination of metadata and other contextual data.  Often very useful.  So I am not sure I like the broad definition.