A scope of work is the written list of what an agency will deliver, in what quantity, by when and for what fee. It is the part of a proposal you can hold them to. If a page, a link or a report is not written in the scope, it is not included, whatever was said on the call.
A scope also says what is out: hosting, photography, paid ads, copy you were expected to write. Reading the exclusions is usually more useful than reading the inclusions.
