Time Series Databases are about storing Time Series data. Each Time Series consist of a sequence of time ordered data items. Each item consist of its time stamp and its actual value.

Time stamps are unsigned numbers that indicate the offset in time with respect to a given Epoch. The Media Type of item values is application specific and normally is Numerical or Textual.

As you can see Time Series data left out a lot of information that is needed to get some meaning about it. Specifically the Epoch (normally the UNIX Epoch), Temporal Resolution (normally second or millisecond) of each timestamp and the Media Type of the data values. Without this information usage of Time Series is restricted to a single Program that knows it in advance.

In order to allow multiple tools to be used with the same Time Series, the model is extended to add support for Time Series metadata. Thus removing the need to exchange out of band the information required to get meaning about the Time Series.