This emoji belongs to the emoji flag group, and therefore represents either a country or a particular phenomenon that can be associated with a flag. Which country or phenomenon it is about is usually found in the name of the emoji, which is rainbow flag.
Here you'll find more info about the emoji 🏳️🌈. The emoji rainbow flag also belongs to the internal emoji group Pride och HBTQ. The main group that the emoji rainbow flag belongs to is Flags, a group that it shares with another 268 similar emojis. A lot of emojis does also exist in different variations, for example different skin colors, the emoji rainbow flag 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 rainbow flag 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.
1F3F3 FE0F 200D 1F308
Use in HTML: