The minimum specs in Akash's link are really not that helpful. If you are only interested in editing images, then an i5- processor, such as the later model suggested by Phinny, is more than sufficient. If you intend to edit any video, then I would recommend an i7- processor. 8GB of RAM should be a bare minimum; 16GB would be better. As Phinny says, monitor size brings in a whole host of issues, which only you can answer.