An important difference between repository and source based environments is the split between persistent storage and editing. Repositories can choose any persistence mechanism that they choose, while source systems need to have some universal storage mechanism — which is why they are almost always text files.

The abstract representation may be edited through multiple projections, each projection can show a limited amount of the total information which isn't tied to the actual structure of the abstract representation. Repository systems thus usually show a wider range of editing environments — including graphical and tabular structures — rather than just a textual form.