⌦ Unicode is awesome ! ⌫
Imagine you want to write a letter in another language like greek β or russian Й there’s a character code for that. Imagine you want to draw a symbol like a phone ☎, there’s a code for that.
On Linux : ① just hold CTRL+SHIFT+U, ② release, ③ type your code ④ then press enter.
On windows it’s a bit more complex but in an app like wordpad type a code like 2615 and press ALT+X.
A complete code list is available here : https://www.unicode.org/Public/13.0.0/charts/CodeCharts.pdf