Question: What are the dll (dynamic link library) files?
Answer: DLLs are dynamic modules that contain common functions that are required by a number of different programs. Instead of providing all of the required processing in every program that needs it the common functions are placed in dynamic link libraries so that you only need one copy of a given set of functions instead of one copy being included in each program that needs it. As there are many functions that all programs need to perform making these functions common results in a dramatic reduction in the amount of space required by the programs as well as ensuring that all of the programs perform the same function the same way.
This article written by Stephen Chapman, Felgall Pty Ltd.