I feel this is my best photo as it’s a good example of a shallow depth of field. The sharp focus of the flowers make it easy to distinguish them from the background.
Speaking of which, depth of field is an element in photography used to create a sense of depth in a photo. Ultimately, it controls what is in focus. Whatever is in sharp focus in a photo is the main subject. Depth of field helps viewers pinpoint what is the main point of interest in a photo that may be harder otherwise.
The term “depth of field” is tricky. It refers to the area from near to far (hence the term depth) that is in focus. You are right that your example shows shallow depth of field. Depth of field doesn’t really create a sense of depth in a photo however. Perspective does that.