Mike Dunford agrees with Denyse O'leary in The Big Difference Between Creationism and Intelligent Design. He says,
It's extremely uncommon for me to find myself in agreement with Denyse on anything (and it's not a comfortable feeling), but in this case I do think she's got a good point. Creationism is certainly explicitly based on the Bible, and Intelligent Design certainly is not.There are several different ways of defining "creationism." I prefer the definition that refers to "creationists" as people who believe that the universe was created by God. In some cases God just set up the original universe with all its laws of physics and chemistry, while in other versions of creationism he/she did some meddling after the initial creation event.
Young Earth Creationists are those who take the Bible literally. Old Earth Creationists are creationists who accept some parts of science and reject a literal interpretation of Genesis. Intelligent Design Creationists are creationists who believe that there is scientific evidence to support the creation event(s). Some Intelligent Design Creationists are also Young Earth Creationists while others are Old Earth Creationist and still others are closer to Theistic Evolutionists.
The supporters of Theistic Evolution are also creationists because they believe in a creator who created some part of the existing universe while, at the same time, accepting most of evolution. Deism is the softest version of creationism and the one most compatible with science.
I think the Wikipedia article on Creationism has it right when it says,
Creationism is the belief that humanity, life, the Earth, and the universe were created in their entirety by a deity or deities (typically God), whose existence is presupposed. In relation to the creation-evolution controversy the term creationism (or strict creationism) is commonly used to refer to rejection of evolution. The wide spectrum of such beliefs includes young Earth creationism holding a very literal interpretation of Genesis, while old Earth creationism accepts geological findings but rejects evolution. The term theistic evolution has been coined to refer to beliefs in creation which are compatible with scientific findings on evolution and the age of the Earth.