What cubed means
To cube a number, multiply it by itself three times. 2 cubed is written 2³ and equals 2 × 2 × 2 = 8; likewise 3³ = 27 and 10³ = 1,000. The name comes from the cube: a box with 4 cm edges holds 4³ = 64 cm³.
That is why volume units carry a ³: m³ is a cubic meter and cm³ a cubic centimeter. One cm³ equals one milliliter, which is why engine sizes and syringes often use cc (cubic centimeters). The reverse operation is the cube root ∛, so ∛27 = 3.
Where ³ comes from
³ is SUPERSCRIPT THREE (U+00B3). Together with ¹ and ², it lives in the Latin-1 Supplement block, so it has a Windows Alt code and the HTML entity ³. The other superscript digits, ⁰ and ⁴ to ⁹, sit in a separate Superscripts and Subscripts block. Some fonts design the two sets differently, so x³ next to x⁴ can look a little uneven.
Characters such as ㎥ and ㏄ pack a whole unit into one square glyph. They come from East Asian typesetting; in normal English text, m³ or cm³ typed as separate characters is the clearer choice.
How to type the cubed symbol
On Windows, hold Alt and type 0179 on the number pad. In Word, type 00B3 and press Alt + X, or select a normal 3 and press Ctrl + Shift + =. In Google Docs, select the 3 and press Ctrl + . to raise it.
On a Mac, open the Character Viewer (Control + Command + Space) and search for "superscript three". On Android, Gboard shows ³ when you long-press the 3 key on the symbols keyboard. On iPhone, copy ³ from this page or add it as a text replacement.
In HTML, use ³, and in LaTeX x^3 or cm^3. For more raised characters, see superscript symbols, and for areas, the squared symbol.