A:
There are three (3) TV series made by ViZIO; Series X (highest level), Series M (mid-level) and Series E (lowest level). There are a number of technical differences between the series. For more information, go to the link:
http://digital.ni.com/public.nsf/allkb/929C108734C102AA86256F27005169C8
There is a new Series P which is VIZIO's UHD (4K) TVs.