AXIOM NameSpace confusion

[saipraneeth nallapareddy]

hi members

i am new to web services, i am using apache AXIS2, now i am going through AXIOM, while creating the NameSpace i have come across two methods

  public OMNamespace declareNamespace(String uri, String prefix);
//another method
createOMNameSpace(String uri,String prefix);  

what is the difference between these two because the former one creates the NameSpace what about the later one, can anyone explain.