Question regarding patches

Sorry if this is not relevant to kernel. But since I am patching the kernel - Please consider this as a uber beginner question to ask on this mailing list - forgive me for that. Now my question is - What "@@ -321,7 +321,8 @@" mean in this snippet from the patch - diff --git a/exec.h b/exec.h index 722c620..6abb687 100644 --- a/exec.h +++ b/exec.h @@ -321,7 +321,8 @@ static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages); -- Shraddha