You are looking at the most important, and most abundant thing on the web. You can't see it, unfortunately, because it's very small… aaaaand it's invisible — so having a magnifying glass doesn't really help here. But still.
I'm talking, of course, about
U+0020; not to be confused with the band U2, who are just as ubiquitous, but far less useful.
This unicode point, representing the humble space character, is between every word, in every run of text, on every page of the web. And it has a very special characteristic: it's not sticky like glue. If two words are neighbors but there's not enough room for both of them, the space will free the second word to wrap around and start a new line.
Before getting into flexible containers, viewport meta tags, and
@media breakpoints this humble character is what makes the web fundamentally 'responsive'. That is: able to change the layout of its content to suit different devices, contexts, and settings. Browser text does this automa