Fundamental theology should not be confused with Christian fundamentalism.
Fundamental theology, in John Hardon's Modern Catholic Dictionary, is a "branch of theology which establishes the fact that God has made a supernatural revelation and established the Church, founded by Christ, as its divinely authorized custodian and interpreter.".[1]
Encyclopedia.com, using an excerpt from New Catholic Encyclopedia, states that "fundamental theology", a "very literal translation" of theologia fundamentalis, is "commonly understood within Roman Catholic theology [...] [to] refer to the introductory tract that treats the nature, possibility, and existence of revelation", and is "often used today indiscriminately" with the term foundational theology.[2]
Unlike apologetics, fundamental theology does not directly work towards evangelization, but rather towards the analysis of where and by what means God brings human beings to assent to his Word.[3]