OK, thanks, I guess it depend on the organization. In the large companies I am familiar with, "Executive" is a definite formal status, and most managers are not executives.

But I see that "senior management" can be used as a synonym for "executive." Still, most managers are not executives, even where that terminology is used.

Also, but some fast-track up-and-comers are executives -- these might be called junior executives.

executive is usually responsible for an entire function

I don't think so. Do you mean an executive is responsible for a function like marketing across the corporation? There are definitely VPs of Marketing and VPs of Development in charge of one part of a company. There are non-execs who are in charge of marketing for some smaller piece of the company. There are execs who are responsible cross-functionally for a profit-and-loss line of business, not one function.

Instead, it seems to me that executive is an arbitrary, though formal border between two groups, and, though no one says so out loud, the underlying difference is what I said in the post.