The Visual C/C++ Redistributable files contain the runtime elements needed to run an application created with Visual Studio on a computer, especially if Visual Studio isn't installed on that computer.
Software programming typically references or calls software routines from a standard library of common functions. In the case of programming created through Visual Studio, including Visual C and Visual C++, the files containing the common functions and routines are called "redistributable files," which means these files can be freely distributed along with the programs that reference them. A Microsoft redistributable file can be shared by many programs all needing the common functions related to a particular version of Visual Studio or its programming languages.
You may have several versions of redistributable files on your computer. And you may be wondering if you need them all. Chances are that you do need them and shouldn't remove them. Because the programming will reference the version of the redistributable file in existence when it was created, it must be there for the program to run.