Specifically for x86 (32-bit) systems. Note that 64-bit systems usually require both the x86 and x64 versions to run various applications.
The file is the installer for the Microsoft Visual C++ 2005 Service Pack 1 Redistributable Package (x86) . It installs runtime components of Visual C++ Libraries required to run applications developed with Visual C++ 2005 on a computer that does not have Visual C++ 2005 installed. Official Download Link download link file vcredistx862005sp1x86exe
If your system lacks this runtime package, you will usually see a variation of the following error pop-ups when trying to open specific apps: Specifically for x86 (32-bit) systems