What is the difference between shirk (associating partners with Allah) and kufr (disbelief)?

Question:
What is the difference between shirk (associating partners with Allah) and kufr (disbelief)?

Answer:
There may be a distinction between them in meaning, but the ruling is the same. The disbeliever and the one who associates partners with Allah have all exited Islam; they are all in the Fire. However, the one who calls upon other than Allah and associates partners with Allah in His worship is labeled with the name of shirk (associating partners with Allah). If his disbelief is due to arrogance regarding the religion of Allah, or denying what Allah has made obligatory, or making lawful what Allah has forbidden, he is labeled with the name of kufr (disbelief). Each one is called a mushrik (one who associates partners with Allah). They are united by the presence of a nullifier from the nullifiers of Islam. If a nullifier from the nullifiers of Islam is present, he is called a disbeliever and he is called one who associates partners with Allah.