well, to answer this would take a lot of time but i turn to Allister McGrath's excellent primer "Christian Theology: An Introduction"

Theology is formed of two root words - theos (God) & logos (word), equaling a definition of theology as "a discourse about God" or "God-talk" as my professor in seminary put it. So, one could say that the manner in which we discuss the nature and actions of God is how we form a doctrine of God.

Seriously, get McGrath's book on Amazon - it helped me a lot.