When looking at certain written documents, texts, it is not unusual to notice that in many, the paragraphs can succeed one another, without the slightest "breathing, "spacing".
If by chance the written words are accompanied by visual elements, be they photographs etc., these are often regrouped together in the centre or at the end of the publication, probably for reasons of printing cost or to facilitate or simplify the presentation.
I believe that it is extremely important that illustrations and the visual and graphic elements be side by side, and thus form a "whole".
This graphic visual material which includes annotations, be they printed or hand-written, are called "images de pensée" which one may translate as "thinking images", or "images of thought".
These images can be separated into different types, which can express concepts, key ideas, design sequences, serious cartoons, drawings which one executes in the search of a design or a project, condensed diagrams.
The other drawings, like the ones which one makes while travelling are of a different nature.