Depth in photography refers to the illusion of three-dimensional space within a two-dimensional image. A photograph with good depth gives the viewer a sense of distance, scale, and perspective, and can create a more immersive and engaging image. 

Depth can be created in several ways, including the use of foreground elements, leading lines, and atmospheric perspective. Placing objects in the foreground of the image can help to create a sense of scale and distance, while leading lines can guide the viewer's eye through the image and create a feeling of depth. 

Atmospheric perspective, which involves using changes in color, contrast, and focus to simulate the effects of distance and haze, can also create a sense of depth in the image. 

Creating depth in photography requires careful consideration of the composition, framing, and lighting of the image, as well as an understanding of the technical aspects of photography such as aperture, depth of field, and perspective.