Embird Manager and Embird Editor are just two different modes of operation for Basic Embird. They both come with the Basic Embird. You can then buy separate alphabets and the cross stitich modules.
I own an old version of Embird and really like it. It allows me to convert designs from different formats into my machines format (Pfaff 7530). I only occasionally use my embroidery capabilites. However this program is very useful and has done everything I need. The Basic Embird does NOT allow you to digitize your own design. For that you would need to add the Embird Studio module.
Here is the link to the description of what the 2 different modes does.
http://www.embird.net/sw/embird/features.htm