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.

This is a unique “code point,” or hexadecimal (base 16) number within the Unicode world. If you know this Unicode number, you can get Apple to display it in the Character Viewer. (Press the ...

A malicious package in the Node Package Manager index uses invisible Unicode characters to hide malicious code and Google Calendar ... attribute from the event's HTML page, which holds a base64 ...