Define properties visible in the header area of each case. For every casetype you can define data fields, which contain identifying data for a case and will be visible always in the header part of the case form. Samples could be customer name or order id, in general information which is helpful when visible on top of a case. According to this definitions, these Header data fields appear later at run-time, while processing the case. Then the users, working on that case, can enter these kind of informations.
Define it yourself
You can define these data fields yourself in the browser. There is no other tool needed to do so. You define the field's type, name it and it's done.

You have available three fields in that header domain of the case data form. Think of it as naming a folder on your PC, except that you have three fields available. In general, you can compare cases as kind of folders like you know it from your PC, but Cases are much more powerful, safe and rule-based.
Imported / Uploaded
In the Enterprise Edition, header data can be imported from an external data source. The informations are then made available as so called 'information objects'.

Such information objects are able to reflect complex data structures, supporting all kind of data types known today. In this case, users can just select header field's data from exising information objects instead of entering manually.
Processing Result
The information objects as well as the properties (header data fields) visible in the case header can be created or updated as part of the result of processing a case or while processing a case.

It's quite often, that these kind of master data (long living data) will be created or updated as part of the activities from processing a case and the data (short living data, processing information) collected while working on the case.