Marketing is the broad process of getting your company positioned so that the messages and content communicated by its advertising will then be
(1) received positively and
(2) understood accurately and
(3) accepted as valid. 

Those three steps are related but they are each distinct.  If this still sounds fuzzy, re-read the paragraph and think about it before proceeding further.

Although the process of marketing may be diffuse and although the actual techniques of marketing widely differ from one company to another, the objectives of marketing remain remarkably constant.  Trade shows, authoring papers, and attending industry meetings, making speeches, serving on committees, and community projects can all be part of a marketing program.  Making your entity visible in a positive setting is the key concept behind marketing.  Marketing is not selling or advertising your specific product or service.  Each of those functions must be budgeted and pursued in its own terms.  Marketing is different.

For example, by writing this paper I am engaged in marketing the entity with which I am associated.  I am specifically not advertising the activities of the entity nor am I selling you anything.  Notice that the content of this paper has nothing directly to do with what my particular organiza­tion does as its business activity (i.e., investing long-term equity capital in promising young ventures).  However, you, as the reader, end up able at least to form some initial attitudes about my organization as a result of reading this paper.  The way I write and the way I handle ideas provide you with a basis for forming certain expectations and attitudes about my organization.  Hopefully, these are positive.