What is the difference between a disbeliever and a polytheist?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.

The difference between a disbeliever and a polytheist was explained by Imaam An-Nawawi in his explanation of the Hadeeth narrated on the authority of Jaabir in which the Prophet, sallallaahu ‘alayhi wa sallam, said that between man and polytheism and disbelief is the abandonment of prayer. [Muslim]

He said that disbelief and polytheism may be used interchangeably to mean disbelief in Allaah. However, they may be used differently: polytheism may be restricted to the worshipers of idols or of any other creatures while admitting that Allaah is their god. An example of this is the pagans of Quraysh.

Thus, disbelief is more general than polytheism.