Question Author
I am amazed and grateful at the replies I have had....
Thank you hopkirk, daffy654, always confused (that could be me also...), dollie65, rojash, mcmouse, hc4361,
Davethedog gave me the explanations I would have liked from the assistant at PC World....
I have decided on a desktop and, since I am happy with the keyboard and monitor, I shall keep those. They are in my study.As I care for my husband who has got Alzeimher's, I shall also buy a laptop to use when I am in his room.Many , many thanks to you all.