For exe files, I suppose the differences are nearly unimportant.
But to start an exe you don't even need CALL.

When starting another batch it's a big difference,
as CALL</code> will start it in the same window and the called batch has access to the same variable context.
So it can also change variables which affects the caller.

START</code> will create a new cmd.exe for the called batch and without /b it will open a new window.
As it's a new context, variables can't be shared.

Using CALL</code> can change the parameters (for batch and exe files), but only when they contain carets or percent signs.

call myProg param1 param^^2 "param^3" %%path%%
Will be expanded to (from within an batch file)

myProg param1 param2 param^^3