
Android Beam debuted in Android 4.0 Ice Cream Sandwich, which was kind of cool at the time, but not all that useful. With Android 5.0 Lollipop, Google has upped the game by adding Android Beam to the Share menu and allowing you to send files, documents, or even photos from one phone to another phone by simply touching the two devices together. It will even work for files or photos that are stored in the cloud, as in not physically on your device. Assuming both devices have NFC, and at least the sending device has Android Lollipop or higher, it's quite easy to do.
If you prefer to watch the video, scroll down to the bottom to see how the new Android Beam works.
Beaming a file or photo is as simple as opening the app that's associated with it and tapping on the Share icon. You should see Android Beam as an option. Just tap on Android Beam to initiate the process. All you need to do it touch the backs of both phones together, and the file or photo will be transferred. So for example, let's say you want to send a photo. Just open the Gallery app and find the photo. Tap on the Share icon, tap on Android Beam, and touch the backs of both devices. Both devices will get a notification that the Beam was successful.
For files, you might have to use an app like Astro File Manager or ES Filer Explorer. If it's something that is already in your download folder, you can simply use the Downloads app found on many Android devices. However, some manufacturers offer their own version of a file manager that will also work.
Astro File Manager Example



Downloads App Example



The other cool thing about Android Beam is that it will work with stuff that's in the cloud. Say you want to share a photo or document that is in Dropbox, but it's not physically on your phone. Just use the Export feature and select Android Beam, and you will send the photo or document to another phone the same way as if it was literally on your phone. It's pretty slick. Note: you can't use the Share feature in Dropbox since it sends a link to the image or file rather than the actual file itself.
Dropbox Example



You can also use Google+ photos as well as pretty much any other cloud service. The majority of them should work with the Share menu, including Google+ photos.
I put together a video showing you how it all works.

I hope this guide helped you. Please let me know if I missed anything, and be sure to hit up our other Android Lollipop guides.