Depends on the location and where you work. Some places an LPN is on the same level as an RN, and some places an LPN just another CNA. If you have to make a choice always choose to be the nurse not the nursing assistant. Not to say that there is anything wrong with a CNA. That needs to be a stepping stone to where you want to be. If you truly want to be in the nursing profession, choose the LPN. More pay and more responsibility. Again I say this based only in my state. I can't speak of any other area.
I have seen LPN's on the med surg floor work beside that RN and I could not tell the difference. You do however, know who is the CNA or the tech.
CNAs primarily do bedside care, such as bathing, vital signs, turning and positioning patients; more advanced ones may do dressings, glucose testing, catheters and such. They are even doing phlebotomy at this point, at my hospital. LPNs are the first stepping stone into the nursing hiearchy that in addition to the previously mentioned skills administer medications, do dressings, treatments, may hang secondary IV (piggyback medications), etc. The RN does assessments, more advanced nursing skills such as pic-lines (although I hear some LPNs are able to do that as well), TPN, IV push medications, and such. I really spoke basic, there is more, but look up in your state board of nursing to learn what they each do in your area.