A hypha is a long, branching structure of a fungus. But in Mycorrhiza Wiki, it's a unit of content. A hypha may be a piece of text or a media file (with optional description). I refer to every page of sona as hypha (plural hyphæ).
See a page in the wiki's help to better understand hyphæ.
Don't ask me why, but I am quite a fan of old orthography. For English, I use the ligatures æ and œ as well as ï and ö to mark vowels that aren't diphthongs or digraphs. Hence, the plural of hypha is hyphæ. Don't @ me.