Change that builds from one level to the next is described as while development that occurs in distinct stages or steps is

continuous; discontinuous

Explanation:

In continuous change, there is the steady transformation of processes in which what was achieved at a point in the process was built on the milestones from previous processes. A child’s physical growth is an example of a continuous change as the height are being added in incremental inches year after year.  

Development can be discontinuous when it happens in unique stages, which could be at some specified time or age.  The change here happens in a sudden.