For those who are unfamiliar with Android Beam, this was a feature introduced several years ago in a much older build of Android. Basically the idea was that you could tap two Android smartphones together to form a link between each other, and from there you could transfer small files such as images, contact information, websites, documents, and more.
However the downside is that because it uses NFC and NFC can’t really handle large files all that well, it means that the feature is not as useful as it could be today. Plus there are so messaging apps these days that allow users to share such files, plus internet is a lot faster too which means that uploading it to a cloud storage service like Dropbox and sharing it with others is very much feasible today.
The feature won’t be deprecated straight away and is expected to be deprecated in future Android builds, presumably Android Q which is due for a 2019 release, but it’s something to take note of in case this is a feature that you still use from time to time.