Definitions for "Orthologs"
Homologs produced by speciation. Orthologs are g enes derived from a common ancestor that diverged due to divergence of the organisms they are associated with. They tend to have similar function.
Genes that code for proteins with a similar function, but exists in different species
Sequences from different species that perform the same biological function and are likely to be evolved from a common ancenstral sequence. See Paralogs.