Aperture – Control the amount of blur or sharpness around your subject.

In this image there is a wide Depth of Field giving a smaller lens opening. This means that the area of focus will be wider.

Settings

Shutter speed: 1/3

Aperture: 22

ISO setting: 400

In this image there is a narrow depth of field which will isolate your subject from the background.

Settings

Shutter speed: 1/180

Aperture: 2.8

ISO setting: 400

In this image the depth of field is short or narrow. Notice how the subject is sharper than the background.

Settings

Shutter speed: 1/30

Aperture: 6.7

ISO setting: 400

Focal length is the distance measured in millimetres between the point of convergence of your lens and the sensor or film recording the image.

depth of field is how much of your image is in focus. A wide depth of field would have the whole shot clear in camera however a shallow depth of field would focus in on one point and blur the background.