The Iliad and the Odyssey use very similar artificial poetic languages and vocabularies (though some words appear for the first time in the Odyssey and most of them are words that are expected to be more recent words).
Even so there is a very noticeable difference in style between the two works, and the easiest way to describe this difference is to say that the Iliad seems masculine, while the Odyssey seems feminine, i.e. the former is like an action movie, which spends a lot of time with the description of matters interesting for males, e.g. about efficient ways of killing or maiming your opponents or of gaining glory on the battlefield, while the latter is like a chick flick, where the main interests are about love and romance, stories about powerful independent women, descriptions of various female skills, clothes, food and gardens, and it includes even feminist complaints about the lack of equality between sexes.
It is very unlikely that we will ever know anything certain about the identity of the authors of the Homeric poems, but reading carefully the two texts, especially in original, gives the appearance of two closely related authors, but nevertheless of different sex.