Now generally, when examining change in any complex system then you'd use a map because the system contains many evolving components and the interaction between them is also important (see figure 1).
Figure 1 - A map
The history of each component is simply a movement from left to right on the map and this can also be viewed on the evolution curve - for example, you can examine the change of computing infrastructure from its genesis with the Z3 to commodity forms today (see figure 2)
Figure 2 - Evolution of a single component (computing infrastructure)
However, sometimes it is useful to simply focus on the current state of change and view the position of all the components of a current map on the evolution curve - see figure 3. This is part of a process known as profiling.
Now, the components shown on figure 3 are all independent and they are all evolving along the same pathway. Creating profiles is an extremely useful technique for competition and one I've mentioned beforehand, however for the time being I simply want to mention it.