Question about <img src=""> in CSS

Please help me with a couple of questions about following style sheet element. The url('blue_field.jpg') form is strange to me. Can this be rewritten in <img src=""> form? Any reason why not? Could I write
background: <img src="/pic/blue_field.jpg">;
Also, what is (repeat-y top left) ?? I have never seen this either.
Thank you.
Ed Shaw
-----------------------css-----------------------------
Links {
background: url('bluefield.jpg') repeat-y top left;
padding: 10px;
margin-top: 180px;
width: 150px; font-style:normal; font- variant:normal; font-weight:normal; font-size:10px;
font-family:verdana, sans-serif
}
-----------------------css-------------------------

I do not think you can write
background: <img src="/pic/blue_field.jpg">;

url(LINK) is just the syntax used in CSS.
LINK is what you put in your src attribute in your image tag.
Works the same way.

(repeat-y top left) that is just setting up the attributes for
the bg-image. It will repeat in the y direction and be aligned
top-left. The background attribute is a shorthand attribute
for five other seperate attibutes. They are
background-attachment, background-color, background-position, background-image, and background-repeat.

the background css2 specs;
http://www.w3.org/TR/CSS2/colors.html#q2

Thank you, chowmein, for your kind assistance.
I understand now.
Ed