Storage space question when members upload photos to their posts

I'm not sure if I'm posting this question in the right section, but here we go.

My forum, if successful, will have a lot of photos uploaded by users in their posts and photo contests. I prefer they have their own photo account elsewhere and hotlink their photos. However, this can be a nightmare, like the problem with postimage.org this week changing their domain, and photos can't be hotlinked to forums or websites, so all of those pics disappeared on forums. And last year photobucket started charging members, and those who didn't/couldn't pay had their pics disappear from forums.

So I'm thinking about doing what some forums do: have the members upload their photos to their posts.

Since I have the free forum, how much storage space (if any) will this take on my forum? The free package says I get "20 Mo". What is "Mo"? Is that like a GB/gigabyte? I'm wondering if 1,000 photos uploaded by members over time would exceed this?

Thanks.

Storage space only applies to attachments and the gallery.  The host an image button in the editor is to an image host, not your forum.

I figured out that mo=mb and go=gb in the USA.

So, when members of the forum attach photos to their posts, is this counted as an attachment?
Or does the forum software put a link to it so that it doesn't count as an attachment?

This is an important question because the free forum allows a maximum 20 mb/mo.

For example, if one photo is 200 kb (or mo),
Then twenty photos of the same size would be 2mb, and
200 photos would be 20 mb/mo.

That would be the maximum for the free forum, correct? Or do those member photos uploaded and attached to their posts not count as attachments and are links instead?

Thanks.

If a member uses the host an image button in the editor, it has nothing to do with the storage space of your forum.