The difference between informative texts and other types of writing and literature is the purpose for which these texts and other types of writing and literature are written.
Informative texts are simple documents whose purpose is simply to inform and educate a reader on something, which is why it only uses simple facts and data, with no opinion or personal positions, or messages. It is very straightforward and simple. The language, therefore is also very simple and straightforward and it does not seek to lead a reflective reaction on the part of the audience, simply to expose facts and data.
But other types of writing, like poetry, and literature in general, are much more complex and their purpose vary depending on the writer and his/her intentions with the text. The language used, therefore is more complex and it seeks to produce reactions from their audience that do not simply achieve the goal of informing or educating, but much more complex reactions.