In HTML, you can declare the Character Set for the file. Here's example of setting it to be UTF-8 (Unicode):
<meta http-equiv="Content-Type" content="text/html;charset=utf-8">
If you don't understand what is Character Set and Encoding, see: UNICODE Basics: What's Character Encoding, UTF-8, and All That?.
Once you declared your character set, you can have characters from that character set in your HTML file.
UTF-8 (Unicode) contains all the world's language's characters. Here is a sample of characters from Unicode:
“ ” ‘ ’ € £ ¥ © ® ™ ¶ † ‡ — é å ø è ü θ π α β → ← ↑ ↓ ↔ ↗ • ‣ ♥ ★ ± ≤ ≥ ≠ ≈ ° ∑
For more examples, see: Sample Unicode Characters.
Another way to show special characters in your file is by so-called “character entity”.
For example, the bullet symbol • is Unicode character number 8226. In HTML, you can write it as
The number 8226 in hexadecimal is 2022. Sometimes you only know the hexadecimal number of a character. You can write it using hexadecimal like this
For some commonly used characters, HTML provides “named entity” for them. For example, the bullet character can be written as
For a complete list of named entities, see: HTML/XML Entities List.