A projection allows the developer to have a custom set of fields from a data element. This projection operates on a single data element, and has a set of reference fields from the original data element, as well as a number own calculated fields.
There are multiple uses for a data projection. A first use is to have a certain set of data available, both in the front-end and the back-end. For example, a user input only needs the name and the password, instead of all of the variables. Secondly, the calculated fields allow a logical module from the reference fields. An example would be if a file needed to be downloaded, the reference fields would be a root folder, a filename and an extension. A calculated ‘full path’ field could give the composed link to the file.