Hello @DiCarloGroup14 ,
Can you elaborate where you're seeing this term? Is it showing up in an email's reporting or in your contacts as a source?
Thanks for the additional clarification. This seems to be regarding the Engagement tab in the contact details. Some open engagement is being listed as "Opened [Email Name] on other device type." As @SuganthM pointed out the other options are desktop and mobile devices.
"Other device type" should be for anything outside the range of standard desktop/mobile such as a smart watch, video game console, or something like Apple TV.