This is a simple online tool which lets you generate "fonts" which you can copy and paste to Facebook, Twitter, Tumblr, Instagram, YouTube, other social media plaforms and wherever else you want on the internet! It generates the fonts using a series of Unicode symbols, which is what allows you to copy and paste them. So in-fact, they're not actual fonts, but series of symbols. But if you just want fonts for Instagram bio/comments or whatever, then this is just semantics! They work just like fonts do :)
In case you're wondering, "Unicode" is a computing industry standard which defines over 100,000 symbols which can be used in all fonts. All the letters that I'm typing right now have unicode "codes" which determine how your browser renders the characters. Fonts are just a way to define different ways of rendering some of these characters (mostly just the letters, numbers and punctuation), but some fonts may specify a large number of symbols and special characters also (these are typically called "unicode fonts").
So yeah, a "font generator" would actually generate font files, so this might be better described as a "pseudo-font generator". I called it "copy and paste fonts generator" just because the title was long enough already, and most people probably don't care :p
If you try to copy and paste a generated font somewhere and it doesn't work (for example is you just see a box, or a diamond with a question mark in it), that's probably because the website is using a font which doesn't support those characters. With time, the more popular fonts like Arial, Open Sans, etc. will hopefully be updated to include many new unicode symbols so that we'll have more usable symbols to play around with, but until then we've just got to make do with what we've got.
If you know of any other fonts that you want me to add, then please let me know! And feel free to copy and paste your creations into the comments section below to test them out before pasting them into your instagram bio or Facebook name :)