Hello! This page lets you generate special text symbols and all sorts of cool fancy text characters by simply typing your normal text in the first box, and then all the special text fonts will be output in the second box.
You can copy and paste the special text into your Instagram bio, and to other places that support Unicode characters. I've noticed that lots of people use these characters to create a stylish name for their Twitter account, and a few other social networks. It helps you stand out.
If you're wondering how this works, then here's the story: There are over 120,000 symbols in the Unicode standard. The normal alphabet is 26 characters, and the numbers take up an additional 10, plus punctuation and all that - and so in total, your keyboard probably has a maximum of a hundred or so symbols. These are the most common symbols used, and so it makes sense to put them all on the keyboard - there's a limited amount of space. But there are over one hundred thousand more! So how do you "type" these other symbols if they're not on your keyboard? Well, you can't - but you can get them from webpages like this! Wikipedia has a big list of characters here.
So, in amongst those 100k characters, there are lots that look like our normal alphanumberic characters on your keyboard. In fact, some of these characters are just bold, or italic, or cursive versions of the Latin alphabet, or other versions, styled in some particular way. A lot of these special letters were introduced to help math researchers express the different abstract mathematical objects in their equations more clearly.
So now you know a bit about how this special text stuff came into existence. Could we just call these special characters "special fonts"? Well, technically, no. A font is something that is designed to change the visual appearance of each unicode character. So if you copy and paste the characters, the font doesn't come along for the ride. Font files are specific to a particular webpage, whereas the characters/glyphs/symbols themselves can be copy and pasted between websites.
Some of these fancy text symbols may not work properly on other websites, and that's because they're using a font which doesn't support all of the unicode characters. If the text symbols aren't even working on this website, then that means that your browser doesn't yet support the Unicode ranges required to get it working. Try upgrading your browser to Firefox and you should see all of the special text symbols in that case.