In Bootstrap 3 we have a font that lets us use glyph icons, but in Bootstrap 4 there were no fonts and glyph icons can't be used. I want to know why they took away glyph icons, and what the replacement for the glyph icon in Bootstrap 4 is supposed to be.
There's a question about this on the Bootstrap repo. Quote:
While icon fonts in general do have some issues, I don't recall that being the primary consideration for dropping them. The more pressing concern was that (A) some folks don't need/want icons (B) many folks were using other icon fonts (such as Font Awesome); for folks in these circumstances, Bootstrap including its own icon font led to unnecessary bloat. Plus, dedicated icon font projects could do a better job than us.
I'd recommend using Font Awesome for icons, as: