Difference between "Save As PNG" and "Save For Web" in Photoshop CS5

Question

I saved a PSD file as a PNG file through the File > Save As... option and then through the Save for Web and Devices option as PNG-24 format.

Is it safe to say that the first way of doing it is already PNG-24 format, since I compared both and they look similar although the file size isn't exactly the same? I have no other bit choices other than PNG-8 format to compare, and that obviously looks different from the PNG saved using the first method.

Answer 1

You can check by right checking the details of the saved file. In Windows the example is to right click, select properties and go to the details tab. You'll see the Bit depth as one of the details in the attached screenshot.