Ok, I know what I’m trying to achieve but I have no idea on the terminology I’m afraid. This all pertains to schematic, not pcb.
I design my circuits in a very modular manner, with any given module on a single sheet of paper (e.g. The psu is a single sheet). What I want to be able to do in kicad is draw a rectangle around certain groups of components as a visual aid - it has no bearing on the schematic, it’s just a help to the view as to what that section of the schematic pertains to.
What’s the best way of achieving this please? Just drawing shapes over the top or is there a specific way to achieve this?
On the right hand toolbar you’ll find various graphical tools headed by the big T that adds text. These allow you to add graphical objects that are not part of the schematic. You can also edit the line style, i.e. solid, dashed, etc.
You might also want to look into hierarchical sheets if you haven’t already.
Hierarchical sheets are a great option if your circuit diagram does not fit on a single page. It also helps with modular design, and combined with Replicate Layout plugin it can also speed up PCB design.
I do advise against drawing rectangles around every small schematic section though. That adds nothing useful, and it does take time to both draw and maintain. In general, it obfuscates more then it clarifies. To keep different sections on the same sheet separated, a bit of whitespace is a great method. It does not take you any time to draw whitespace, the whitespace moves on it’s own when you are refactoring your schematic. It can help to also add some bigger texts. Big (and/or fat) text (about 2 to 5 times the normal text size) is a great way for other people to quickly get an overview of what your schematic sections are, contrary to a rectangle, which does not have any useful information on itself.
Also, drawing “good looking”, and easy to understand and maintain schematics is a bit of an art form. It takes some time, effort and experience to get it right. (Some people do not even try, and they usually draw truly atrocious and incomprehensible schematics). Some simple and valuable rules of thumb are to keep the general signal flow from left to right (just as in reading text) and to keep voltages “top - down”.