what is the depth of field ?

A: Depth of field is the amount of focus you use in  a picture .

what is the difference between large and small depth of field ? 

A: small depth of field means that they're is a small amount of focus in the picture. Large depth of field means that their is a large amount on focus .

How does your photo show depth of field ? 

A: my first photo shows a small depth of field the front of the  picture is focused while everything in the background is blurred. my second picture has a large depth of field everything is focused in the back and the only thing focused is the lock in the from of the picture .