Subsuperscript[x, y, z] is an object that formats as x_y^z.
x_y^z is the low-level box representation for x_y^z in notebook expressions.
SubsuperscriptBoxOptions -> {opt_1 -> val_1, opt_2 -> val_2, ...} is an option for selections that specifies settings for SubsuperscriptBox objects.
Like everything else in Mathematica, notebooks are ultimately symbolic expressions. When you edit notebooks—or apply high-level programmatic functions—Mathematica ...
Superscript[x, y] is an object that formats as x^y.
Underoverscript[x, y, z] is an object that formats as x_y^z.
Built into Mathematica are hundreds of powerful notational forms that can be arbitrarily combined and immediately accessed through their symbolic representations. Many common ...
Subscript[x, y] is an object that formats as x_y. Subscript[x, y_1, y_2, ...] formats as x Subscript[y, 1], Subscript[y, 2], ....
NHoldRest is an attribute which specifies that all but the first argument to a function should not be affected by N.
PNG
(Mathematica Import/Export Format) Registered MIME type: image/png PNG raster image format. Commonly used for graphics and photographic images on the web. PNG is an acronym for Portable Network Graphics. ...