First, DRM is Digital Rights Management. It is how a seller prevents the buyer from copying the item and then distributing it. It also does other things that are not so desirable (only able to put book on a specific device, etc).
Both the JB Lite and the Aluratek Libre support Adobe Epub DRM (the most popular library DRM format) and (I believe) Adobe PDF DRM. The JB Lite (JBL) also supports Barnes and Noble Epub DRM, has a limited dictionary and doesn't have an mp3 player. Other than that there is not a lot of difference between the devices. Neither device supports Mobi DRM.
If you are going to be buying books from B&N, then you probably should get the JBL. Otherwise I don't see that it really matters. Ectaco has shown themselves to be more devoted to the JB line than Aluratek has to the Libre line (though that could be changing with the addition of the Libre Color).
There are my two cents.
Hope this helps.