When a team of developers write code for a fairly large project, they typically use a version control system for their source code. One of the standard uses is to create branches and migrate changes in one branch to another branch. In sophisticated version control solutions such as git, recent changes to one branch can be captured as a package of diffs and then applied to other branches of the code being developed by other groups of users.
The idea behind Runtime Data Differencing is to apply the diffs at the time the code is executed and not at the time the application is built from source code. This brings some of the advantages to source code control to the problems of complicated application deployments. In particular it can help solve the Component Evolution and the Staging to Production problem. It can also allow an administrator for an application who performs complex administrative tasks to get some of the advantages of a source control system for the administrator's changes.
The focus of the solution is on tables and overlaying tables from a Component on top of the configuration or runtime data of an application. This approach forces a change in how the application is designed and written, but with great advantages gained as the applications evolve over the years.