Unicode has many code points that have visually different representations of the same character. For example, the image below shows all visually different representations of 'X'.

Code points are written in the format 'U+XXXX,' where the 'U+' indicates that it is Unicode, and the 'XXXX' that follows indicates the code point in hexadecimal notation.

These are characters which can be built from multiple glyphs, but they also have a pre-built Unicode point. There are also ligatures that combine multiple characters into a single code point.