Difference between NDA document and Partnership Aggreement

Hi

I would like to understand the difference between NDA document and Partnership Aggreement. My confusion is does Partnership agreement is signed after NDA document ? I am doing one contract with B company located at another country. They told me to sign NDA document first and after then Partnership Agreement will be signed again but when i asked them after how long partnership agreement document will be signed if i provide them nda document at earliest then they did not gave any answer and this is what i am confused about. So what is procedure of signing partnership agreement after nda is signed ? please suggest ?