Configuration control is the control of all the engineering information so that you do not get erroneous information built into the product and modifications are not missed and everyone knows what they are working on. You can imagine the problems that could arise if you had say twenty people working on a particular project, or on the space program for example, thousands.
So you have at the very least one reference drawing/drawings which everyone works too, and the drawing has a date, and issue.
Things always go wrong in engineering, but it is 'configuration control that gets you in the end', hence the saying.