> This model is the basic two-dimensional form. Instead of editing a line, the user is editing in a quarter-plane, with the origin usually in the upper-left corner. Conceptually, the user can move freely in the two-dimensional quadrant. In practice, the editor usually only stores the non-blank portions, as storing an infinite-quadrant's worth of data can be prohibitively expensive. Some systems may impose fixed upper bounds on the width or length of the quadrant.
Sure, that's fine I guess, but this doesn't help me understand how to use or program Emacs. And most of the code is in C, not Elisp.
Anyway, not every programmable editor is programmed in Elisp.
I find helm much better than ido for most purposes. I couldn't live without helm-git-grep - it's how I navigate everything. I even add all my installed gems to a git repo just so I can use helm-git-grep easily when browsing / debugging 3rd party code.
I've gone through maybe 6 editors and IDEs in the last 20 years. I wish I'd started using Emacs 15 years ago instead of 15 months; I'd have wasted less time configuring keystrokes, and be more cumulatively productive.
A buffer is a file opened in the editor. The cursor is called the point, the text selection is called the region and is the text between mark and point. You open files by "finding" them. A pane in the editor is called a window.
Cut is called kill, paste is called yank, and there is no single simple jargon for copy - it's killing without deleting the text.
When coding elisp, you often use the (with-temp-buffer …) macro to do more or less the same thing :-)
Also, several buffers can correspond to one file: "C-x 4 c" runs clone-indirect-buffer-other-window which creates two views on one and the same file. This is not the same as splitting the window: The two buffers can each have their own, different narrowings applied. Say you have two functions defined in one file, they're almost the same, so you want to compare them. Now, clone the buffer, narrow the first buffer to the first function, the second to the second, and now you can run ediff on the two buffers :-) Or you can even open the same file in different major modes at the same time …