A Configuration is a meaningful combination of versions of files. A Configuration Management System is a system which makes it easy to record useful configurations and to reproduce them easily.

For example, if your product is built from a collection of source and include files, then all the files that were used to produce a given release are part of that release's configuration. But you edit files from time to time, creating new versions of those files. So, even though the same files are used to build the next release, they are different versions of those files.

Not all combinations of versions of files are useful. Mixing older include files with newer source files might not even compile! We call a useful combination of versions of files a configuration. If a combination is not useful we call it version skew.

You work as usual in your workspace, editing files, compiling and testing. You check files out when you want to modify them and you check them back in when you are done. You'll learn all about checkouts later in this course.

ClearCase can be used in many different ways with corresponding benefits and costs (in terms of time and complexity). There is room for a lot of strategy in how you use ClearCase, just as there is a lot of strategy in chess, even though there are relatively few rules.