To the laymen, replication and duplication probably mean the same. But to the people in the disc manufacturing industry, there is a subtle difference. Replication usually refers to the process of making CD or DVD from a glass stamper (or mold). When melted polycarbonate is injected under high pressure onto the glass stamper, the bits of information are formed. A reflective layers is then coated on the disc so the laser beam inside the CD player or DVD player can see the data.
Duplication, on the other hand, refers to making CD or DVD by burning data onto recordable media. For that reason duplication is usually limited to short-run smaller or urgent jobs. For large volume production, replication is the most cost effective and the discs produced are of higher quality.
Replication can only be done under highly temperature and dust controlled environment. Duplication can be done in any normal environment such as in the office or at home. A replicated CD or DVD (so called pressed CD or DVD ) usually has artwork printed on the disc using silkscreen or offset printing process. For duplicated CD or DVD, you can either print a batch of recordable media using silkscreen or offset or you can apply a paper label on the disc. Some recordable media have inkjet printable surface on the disc allowing you to print the artwork directly onto the disc with special inkjet printers.

An Autorun CD is a CD that will automatically start a program when the CD tray closes with the CD inside the tray. Autorun is a good feature for the less computer savvy users. It eliminates the steps for the user to click on "My Computer", the CD-ROM drive, and then the program to be run. You will be surprised that many causal computer users don't even know these few simple steps to invoke a program on a CD-ROM. An Autorun CD hides all these "complexities."
It's quite simple to make a CD autorun on a PC. All you need is to include a file call "autorun.inf" in the root directory of the CD-ROM. You can create the file with a simple text editor such as Notepad. If you use Notepad, make sure to quote your filename when you save the file otherwise Notepad will save the file as "autorun.inf.txt" instead of "autorun.inf". In its simplest form the file only needs two to three lines. For example:
[autorun]
open=program_to_be_run.exe
icon=icon_to_be_shown.ico
You should replace "program_to_be_run.exe" with your own program and "icon_to_be_shown.ico" with your own icon. The requirement for this to work is that program_to_be_run.exe must be a self-executable file. Simply put "open=index.html" trying to open up a webpage won't work.

2.1 Autorun a PowerPoint Presentation
Same as HTML file, a PowerPoint file is not self-executable. You may be tempted to think that the same tactics to handle HTML file should work for PowerPoint. In most cases it will, provides that the users' systems have PowerPoint installed. In case the viewer's system does not have PowerPoint, the method will fail badly.
PowerPoint 2003 now has a "Package for CD" feature. If you author your PowerPoint within PowerPoint 2003 then go File > Package for CD > OK. The Autorun.inf file will be created for you automatically. There are also a whole bunch of files including some DLL's. Don't be intimidated by all those files. They are just there for the PowerPoint Viewer so that there is no need for the users to do any installation . You can even go into changing the Autorun.inf file if you want, say if you want to add or change the icon file. A word of caution for international users though. When the autorun CD created by this way is put into the CD-ROM drive for the first time, the program will present a nagging screen asking the user to accept the Terms and Conditions. If your PowerPoint 2003 is a French version, the text presented on the nagging screen will also be in French, even the users' default locale is English.
If you don't have PowerPoint 2003, you can download the PowerPoint Viewer 2003 from Microsoft. Microsoft article "How to use PowerPoint Viewer 2003 to create a Windows autorun CD slide show for earlier versions of PowerPoint" has all the information you need.