CS2 images

Would anyone on here know how to take an image and make "part of it transparent? Not all of it as CS2 does have image opacity option but I can not figure out how to do just a section of an image any ideas?

Open a file in Photoshop with a transparent background. Drag the image into the file, and use the magic want tool to select the area in which you would like to make transparent. Cut the selection out and that area will be transparent.

I'll Give It A Go, Thank You

iNAP, the opacity for the level is on the layers pallete. If you have an object in a layer you wish to make transparent to the layer below it that works well.

What I would think would be easier, is I was hoping I could just highlight or select a section of an image saved as layer and work with the opacity. If I understand this right, what it is, is each separate level of opacity has to be a separate layer correct?