Why should we set /MT to run executable in another pc

I'm reading about /MT and /MD, but I'm a little confused about it

HEAR is something I don't completely understand :

/MT Causes your application to use the multithread, static version of the run-time library. Defines _MT and causes the compiler to place the library name LIBCMT.lib into the .obj file so that the linker will use LIBCMT.lib to resolve external symbols.

what does it mean?