[TenTec] Orion / Jupiter SDR Radios ?

[gdn50 at usol.com]

I'm not an Orion or Jupiter owner and am using older eqipment but I 
see mention in the threads of the Orion of Jupiter being "SDR" radios 
and am curious as to what that terminology means. It's a new term to 
me.

Thanks in advance.

73 Gary
K8IQ