>>40828214a pokemon can have 1 type (monotype)
a pokemon can have 2 types (dualtype)
pokemon types have strengths and weaknesses
those advantages or disadvantages towards other types were determined by the pokemon company, gamefreak.
if the type says its weak to itself, then it is, some types are, such as ghost
ghost is weak to dark, psychic and GHOST
but not every type is weak to itself, then what happens when a pokemon its dual type?
those strengths and weaknesses are added up
if by adding it up
it can resist, or be weak to
if for example type 1 doesnt resits type 1
then if type 2 is weak to type 1
then your pokemon is weak to type 1 even if itself is type 1 and type 2
