what exactly do web hosters do? Options

[rail01]

After you have an idea of a website you want to make, know what you want in it and selected a web host, where does it go from there...?

Do you tell them what you want in it and they do it? Will they have different formats/style you can select from, do you have to make that up yourself or buy it from another site? I know they give you space for what you pay for, but will there be a selection of ways you could have your site done?

Also...will they do the "clickable" stuff for you? example the top of this page says....Layouts, Graphics, Scripts ect. can I tell them what to put up there and they'll do it? Thanks.