This is a simple bold font generator that converts normal text into bold text that you can copy and paste into your Instagram bio, Discord chat, Facebook posts, tweets, Twitter display name, and many other places on the internet. It creates a few different bold fonts so you can pick the one that you like the most.
If you're wondering how this works: The keys on your keyboard are only a small subset of all the actual characters available in the "Unicode" standard. There are tens-of-thousands of them! Over 120,000 as of writing, actually. We can't fit all of them on a keyboard, and we hardly every use the other ones anyway - the common exceptions might be the "TM" and related symbols: ®™© and sometimes accented letters as in "cliché". But just because they're not on your keyboard doesn't mean you can't use them! This generator simply collects together all the symbols in Unicode that are part of bold "pseudo-alphabets". These are alternate versions of the "Latin" alphabet that were included in Unicode many years ago to help mathematicians and other academics better express mathematical formulas and the like when they were communicating over the early internet and in their various computer applications.
So I hope that makes sense! From that you might (correctly) deduce that these bold characters aren't actually part of a separate "font" - these characters actually exist in all fonts, which is why you're able to copy and paste the bold letters into multiple websites online, all of which use different fonts.
You'll also notice that I included a bunch of other special/fancy fonts below the bold ones, just for fun. Enjoy! :)