You pretty much got the idea about library functions. Most C/C++ compilers have a folder named “include” that has a number of “header” files that can be added to a project by using the preprocessor directive “#include” and then the header file in angle brackets ( like #include < iostream.h> ). There are a whole group of standardized header files each with a certain type of pre-built functions. stdio.h ( stands for standard input output ) , for example , has certain functions for input and outputing things to the screen and files. When you include a certaing “header file” you import all the functions in the file to your project , so this can add to your projects size. However , C/C++ is low level enough that you can write many of these functions your self instead of including them , or since many C/C++ have inline assembly language capabilties you can write your own custom set of utilities , if you desire. Many compilers come with executables that allow the user to compile and create their own header files as well. You’ll find C++ to be much more powerful than VB ……..