According to the Unicode Consortium, Unicode provides a unique number for every character, no matter what the platform, no matter what the program, no matter what the language.
If you want to use a fancy character or Emoji on your website, like you see others using on Facebook or their Smart Phone, copy the code before the character to your website. If you want to use the character on Social Media or your Smart Phone, copy the character.
Click on links to the left to see codes and characters for various subsets of Unicode.
Other Unicode sites of Interest: &what; – Unicode Search. Emoji Cheat Sheet shows the short codes for Emoji. Emoji are basically pictures for Unicode Characters. Each operating system has its own picture. On Smart Phones, you can use the emoji keyboard for an Emoji. FileFormat.Info is also helpful with Unicode. Unicode Shapecatcher lets you draw a picture. It then shows some Unicode characters which come close to what you’ve drawn. It tends to only search the more picture-like Unicode characters, which may be just what you want.