This emoji represents a typical white-gray-ish human skull that is placed in front of bones shaped like an X, just like on a pirate flag or the symbol indicating that something is poisonous. Often used to convey feelings surrounding death or that something is extremely dangerous, but can also be used playfully that one is dieing of laughter. Used very often around Halloween.
Here you'll find more info about the emoji ☠️. The emoji skull and crossbones also belongs to the internal emoji group Halloween. The main group that the emoji skull and crossbones belongs to is Smileys & People, a group that it shares with another 472 similar emojis. A lot of emojis does also exist in different variations, for example different skin colors, the emoji skull and crossbones does however not have any known variations.
If you want to copy the emoji in order to use it in for example an email or a chat, all you have to do is click the button "Click here to copy emoji" that is listed below the emoji. The emoji skull and crossbones will then be placed in your clipboard, and you can easily paste it the way you normally paste copied text - for example by pressing ctrl+v (or cmd+v if you are using a Mac) if you are using a regular computor. Please note though that this function is disabled on mobile phones due to techincal issues, there you'll have to hold your finger towards the emoji and copy it the regular way once the dialogue opens.
Below you will also find the HEX code for the emoji together with a prepared example coded in HTML that is ready for you to use directly in a generic HTML document.
Use in HTML: