plugin to separate content from layout

Hey there,

I’m wondering if this functionality exists somewhere (maybe in the form of a plugin or a widget).
I’ll try to describe it as good as Belgian guy possibly can ;).

WordPress can be used as a CMS. But instead of creating full pages, I would like to define blocks of content.
–> In a block you specify which inputs are required, for example
——> a string of max 100chars (which will be used for the title)
——> a photo of size 50px by 50px

Now as the system knows which input is required he can build up a custom form to complete that block.
As frontend, there is some kind of template engine that translate the content just inserted into html.

Of course one page consists out of different blocks. (another example of a block would be a data table, where you just insert the raw data in the ‘input phase’, and that the parser translates it into html).

By doing so it’s incredibly easy to keep your site updated, as well content wise as layout/style wise.

So … Does this exist in some form? ??
Thanks,
Pj