First multimedia, is mostly referring to software programs that incorporate written info with pictures and sounds to create a very appealing and stimulating "production" if you will. The idea of multimedia production is that the more stimulating something is (i.e. the more senses that you involve) the better the message will get across to the receiver and will "stick."
There then obvious areas where multimedia production would be very useful including School, job training, fundraising, political campaigns, marketing of any type, museums, art, etc. Basically anyplace that there is any sort of message that the bearer thinks is not only worthwhile pondering but also valuable to remember.
Until now this type of thing was only for the technologically savvy "children of the computer age." Just like with most other things today however this form of enhanced communication is available via automated tools to the general public. In other words the "children" that understand the technology have created ways for the rest of us to get in on multimedia production without having to go through the pain of learning the intricacies of computer programming of the various media types or the complicated science that goes on behind effective communication.
You might think, wow these are great guys! They are doing something to advance society without expecting to be rewarded with anything but a pat on the back. And...I guess this could be true, but the vast majority of these guys who have developed these multimedia production tools are getting very rich from there sale.
This brings up another useful caution: because people see how popular and profitable it is to develop a multimedia production tool they too want to get in on it. So there are several options too many out there on the market. I say too many because probably half of these products are not worth the couple hundred dollars. On the other hand, if you get a good tool, the investment of 200 to 300 dollars is nothing compared to the amount of money you will be able to generate from the sale of your multimedia product.
So how do you decide? Well, just like anything, go about this important purchase with a touch of cautious and a lot of common sense. Do a lot of research online, in technology magazines, on forums for multimedia production. Look at product ratings on review websites. Talk to friends and other trusted advisors. Look only on pages (or in stores) that are well known and respectable in order to take advantage of the fact that they would not want to tarnish their name by selling an awful product. Lastly take advantage of the common guarantees that allow you to try the product with full refund if not satisfied. Now start looking and have fun!