A to Z Challenge - D

The pond near my house...

Simply put, depth of field is the distance between the nearest object and the farthest object in your scene. In photography,  how your depth of field appears can be affected by your aperture/f-stop, your lens, and the distance to your subject.

 
In some cases, a photographer wants their depth of field to be clear and in focus, landscapes are an example. If the depth of field in the picture above was not in focus, all you would see is a tree! In this photo the entire scene is the subject of the photograph.

Again, my nephew's photo illustrates this better than mine.

In some cases, however, a photographer wants the focus to be not the complete photo, but a specific subject in the scene, an example of this is portraits. Most amateur photographers just point their camera and shoot, not paying much attention to aperture. This gives a photograph where everything is, hopefully, in focus...but all that focus may be taking away the...well...focus from the photo's real subject (a bumble bee on a flower, a child surrounded by a park, etc.). By lowering the f-stop for a wider aperture, a photographer can make a specific subject in a photo stay in focus while blurring the depth of field beyond that point.

Oh, and a trick my nephew taught me...ensure the focused subject is against a contrasting color background to increase the impact (yellow flower against white tablecloth)!

Play with your camera's settings, if you can, and see what you can do.