LaTeX fragments can be processed to produce preview images of the typeset expressions:
You can customize the variable org-format-latex-options to influence
some aspects of the preview. In particular, the :scale (and for HTML
export, :html-scale) property can be used to adjust the size of the
preview images.
During HTML export (see HTML export), all LaTeX fragments are converted into images and inlined into the document if the following setting is active:
(setq org-export-with-LaTeX-fragments t)