When an animal receives both parent genes, and they are in equal proportions, then this is considered to be codominance. When an animal receives a trait from their parents, but it is from a combination of alleles and genes from the parents, then this is considered to be incomplete dominance. Both are non-Mendelian inheritance patterns. In codominance, there is an independent effect of the hybrid, whereas, in incomplete dominance, there is an intermediate of the two alleles of the hybrid.
In codominance, both alleles are conspicuous equally, whereas one allele is conspicuous more than another in the incomplete dominance. The quantitative effect in codominance is absent, whereas the quantitative effect in incomplete dominance is present. These two patterns have a few similarities and differences.