--DRAFT IN PROGRESS Common files make the web page look like they all are part of the same system Start with the point of view of people who use a system. Forget the techies for moment. Assume the system does more than one thing or if it does only one thing, that thing can be seen as having more than one part. Intellectually, that assumption is can be the one you never get past. If that is your situation, get past it anyway. If you can't, please explain why. So now we have a system consisting of at least two things. How can we tell they belong together and they form a whole? The answer is that each of the two things must be different in some way, and the same in some way. That is how software has to be put together. There always are parts that are different that make use of parts that are the same in other parts of the system. The parts that are different are easy to organize, you keep them all separate. There are two ways the parts that are the same can be made. They can be replicated in every part of the system where there are used, or they can not replicated, but referenced by more than one part of the system. The way parts work the same when they are copied vs. referenced is unique to software. If I build a house indentical to yours, I cannot use any of the materials that are in your house. If I did, I would not have a copy anymore. The best I could do is make two houses out of one that would be half the size in every dimension, and that would require making two small door knobs from one. In software, I can make a complete working copy of a whole system by referencing another and to the people using both systems, there would be no difference in any way. Now let's bring the techies back, but not all of them just the application programmers. That is what I am. These two screens are part of Holly's new blog:
