Office Picture Manager - Difference, resize vs. compress

[rtvs]

What is the difference between resize and compress a photo? Both will make
the picture/map smaller, but what is most desireable to reduce the size?

 

[Bob I]

Resize changes the pixel dimensions, compress removes picture content.
See description in Picture Manager's Help. Be VERY sure you keep a safe
copy of the original.

 

[rtvs]

So - to maintain good quality, just resize and don't use compress?

 

[Bob I]

To maintain good quality, don't resize OR compress.