> For the complete documentation index, see [llms.txt](https://nftdeal.gitbook.io/eng-user-guide/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://nftdeal.gitbook.io/eng-user-guide/collection/what-are-collections.md).

# What Are Collections?

Collections are groups of NFTs that are controlled by the same smart contract. 

Before creating a collection, please take note of the following:

* NFTs within the same collection are controlled by the same contract.
* The NFTs within a collection can be different.
* You cannot delete the collection in which an NFT has been minted. 

Here is how a collection will look like once it is created:

<figure><img src="https://1601591342-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FWGLTHXCSQ9PW33ohjmbI%2Fuploads%2Fwk9vb7cVP7epAvS3rhbU%2Fimage.png?alt=media&amp;token=34c3ce31-3f8f-499e-99fc-3e53bb396617" alt=""><figcaption></figcaption></figure>