Theists and strong atheists make statements about the world, the theist that 'god exists', the strong atheist that 'god does not exist'. Agnostics make the statement about these statements, 'one cannot know whether or not: god exists'.
Agnosticism has suffered more than most expressions of philosophical position from terminological vagaries. Examples come from attempts to associate agnosticism with atheism. The "freethinking" tradition of atheism calls not adopting any position with regard to the existence of god, "weak atheism" (or "negative atheism"). However, one can still draw a distinction between weak atheism and agnosticism by drawing a distinction between belief and knowledge, leading those who believe knowledge of God is not possible to claim agnosticism is about knowledge, while atheism/theism is about belief. Agnostic atheism is a combination of both.
Data collection services ,  often display the common use of the term, distinct from atheism in its lack of rejecting the existence of deities. Agnostics are listed alongside secular, non-religious or other such categories.
Other variations include:
- strong agnosticism (aka hard agnosticism, closed agnosticism, strict agnosticism)—the view that the question of the existence of deities is unknowable by nature or that human beings are ill-equipped to judge the evidence
- weak agnosticism (aka soft agnosticism, open agnosticism, empirical agnosticism)-the view that the question of the existence of deities is knowable but the individual has not seen enough evidence or there is evenly-weighted evidence on both sides of the question of the existence of deities.
- ignosticism (aka apathetic agnosticism, apatheism)-the view that the question of the existence of deities is meaningless because it has no verifiable consequences
- model agnosticism—the view that philosophical and metaphysical questions are not ultimately verifiable, but that a model of malleable assumption should be built upon rational thought. Note that this branch of agnosticism differs from others in that it does not focus upon the question of a deity's existence.