Desk Top Model. 21 inch diagonal screen. Version is a mid 2012. Mac OS 10.6.8. Darwin 10.8.0. Keyboard included. Mouse and mouse pad NOT included.
So this is a large screen. I wanted to use it as a display screen for my Mac Book but the 2 versions are not compatible due to age difference. So, if you have a laptop that is 2019 or earlier, you would be able to use this as a display.
FROM APPLE:
iMac models introduced in 2011, 2012, 2013, and mid 2014
To use any of these iMac models as an external display:
The iMac used as a display must have macOS High Sierra or earlier installed.
The other Mac that you're connecting it to must have been introduced in 2019 or earlier and have macOS Catalina or earlier installed.
The cable connecting the two Mac computers must be a ThunderboltThunderbolt or Thunderbolt 2Thunderbolt 2 cable.
24-inch and 27-inch iMac models introduced in 2009 and 2010
To use any of these iMac models as an external display:
The iMac used as a display must have macOS High Sierra or earlier installed.
The other Mac that you're connecting it to must have been introduced in 2019 or earlier and have macOS Catalina or earlier installed.
The cable connecting the two Mac computers must be a Mini DisplayPortDisplayPort cable.