Q: how can I share my photos between my devices

PhotoStream - http://www.apple.com/icloud/setup/

LN

Did you read the reauirements Do you have the required version of iPhoto? Did you log into iCloud in the system preferences as instructed?

No mind readers here - you actually have to share information about your system and your workflow - otherswise answers are theoretical and wild guesses'

LN

purchase it in the App store - or update to it - Once  again no mind readers here - with no knoledge of what you have or what you are doing only general answers can be given

LN

the required version of Iphoto

And obviously it is necessag=ry to knwo the version of iPhoto on each - version of iPhoto is part of the requirements listed in the link I posted

i already provided my devices IMAC OX version 10.8.3 and macbook air version OX 10.8.3

Actually you had not - your profile says that your iMac has 10.8.3 -

iMac (27-inch Mid 2010), OS X Mountain Lion (10.8.3)

nothig you posted mentions the version on your MBA

Sorry that you find this so difficult - why not give the pertinant informatin rather than argue about it - expecially where the complete conversation is posted to exhamine

Photostream requires "Mac with OS X Lion v10.7.5 or later and iPhoto 9.2.2 or Aperture 3.2.3 or later"

Shared Photostream requires "Mac with OS X Mountain Lion v10.8.2 or later and iPhoto 9.4 or Aperture 3.4 or later"

When I posted the link to that information why did you not either read it and figure out the problem youself or post the information about your systems so some else could help

LN