Resolution and dpi are two different terms.
will you be scanning the photos for professional-printing or saving them on computer?
if you want to scan them for saving on computer (for archiving purposes), even 96 or 72 DPI will be enough, because that is the resolution of most computer monitors.
a 600 dpi laser printer can print up to 600 dots of picture information in an inch but a computer monitor can typically display only 96 or 72 dots of picture information in an inch.
if you scan them at higher dpi, for example if you scan a photo in 600 dpi when the display device (for example your computer or laptop monitor) has less dots than the photo, those dots are wasted. in this case, scanning at 600 dpi will only increase the file size (in bytes) but won't improve the printing or display of the picture. (The resolution is too high for that device)
Many thanks for your comprehensive answer.
These are family photographs, which are quite old. My plan was to scan at 600dpi so that in the future, they could, if need be, be professionally handled. In the meantime they would be stored locally on disc and the cloud.
So, in short, our current scanner, capable of 600dpi, would be OK for this project, and no need for a higher resolution scanner?
You are welcome.
Yes, 600dpi is OK for your project.