both these images display on screen at the same size because it's the screen dpi that is important not the dpi that the image is rendered,and they are both 1200x800
The Dpi is only relevant to the printing of the image.
They both come out in size (inches) at nearer to the 96 dpi because most screens are higher than 96 dpi
Dave, thanks for all the effort. However, I do understand pixels and dpi, but I was addressing something far less technical. I noticed that my uploaded images displayed differently in the forum - as in sometimes when you click on the thumbnail you get another thumbnail in a new window and if you click on the filename you get a new window with a full sized image. Sometimes there is no thumbnail. I found that there are several ways to upload a file - drag and drop - +Attach file - the picture icon in the comment window. I have tried all three ways and I found that my files were displayed differently. Not dpi or resolution - I was noticing that the website handled the files in different ways. I guess I did a bad job of making my point. I was trying to figure out why Ralph's picture showed only a smaller version and I was sure that at least one of mine showed at full size with a click. Thanks.