Hi,
AnimalAddictions, and welcome to the forums.
Short answer: Yes you need it. Don't remove it.
Detailed answer: There are many different programming languages out there for developers to write programs (code) in - JAVA, .NET, C++, C#, Python, Ruby, etc. Some of these use a program called a compiler to turn a piece of code (in simple text format readable by humans) into an executable (program, readable by computers and Uber geeks).
Some languages produce executables that also use external files during execution as needed. These are (usually) called runtimes - from AtRunTime, IOW - these files are used by executables *when they are run* (at Run Time) to help keep distributed code smaller. Think of these as one of the most important components in the internal combustion chamber of your car's engine - sure it needs gas, and it needs electricity, and it needs water for cooling, and it needs oil for lubrication. But it also needs air - directly for combustion to take place. No air, no combustion.
The same holds true for executables in certain languages, in this case, Visual C++. These Redistributable files (runtimes) are like the air to your car - they need to be everywhere any type of C++ is run (just as you need air anywhere you want the car to run). Now, Vista comes with a certain version of these, but they are a bit outdated - so sometimes you'll see them having 'service packs' just like your Vista does - they mean the same thing - they are newer, better written.
I hope this answers your question.
I googled it, but I don't speak computer lingo so i'm still not sure if I need it or not. Could someone tell me what it is and what it does in "lay" terms so I know whether or not to uninstall it?
Ted