As nouns the difference between matroid and graphoid
is that matroid is a structure that captures the essence of a notion of "independence" that generalizes linear independence in vector spaces while graphoid is a particular form of matroid.
matroid
Noun
(
en noun)
(combinatorics) A structure that captures the essence of a notion of "independence" that generalizes linear independence in vector spaces.
graphoid
English
Noun
(
en noun)
(mathematics) A particular form of matroid
References
* MathWorld