If you have an iPhone 6s or above, you’ll be able to capture moving pictures called Live Photos. From the Camera app you can toggle this feature on or off with the Live button along the top of the screen. (It’s a series of concentric circles.)
In the Photos app they look just like any other photograph, but you’ll notice a flicker of animation as you swipe through them.
To watch the three-second video associated with a Live Photo, simply press and hold on the photo to animate it.
There are a few different ways to share these pictures with the animation intact, but the best way to show your Live Photos to friends is to send them to somebody with a compatible Apple device via iMessage. Tap the share icon while viewing the Live Photo and choose from the available options.
Bear in mind you can still share the photos via Mail or through other means like social media, but they will be sent as regular pictures with no movement included.