Answer: Supporting a claim about similarities or differences.
Step-by-step explanation:
In writing, a comparative essay is a type of essay that focuses on analyzing and proving the differences and similarities between two or more objects of one category, for example, two theories about life on earth; two novels of the same genre or the life of two important people. For doing this, as in other essays, the writer creates a thesis statement or main claim that expresses his position and then looks for evidence or information in reliable resources that helps the author to prove the thesis statement during ht body paragraph. This implies, in the case of this type essays the textual evidence or evidence from other texts is important because this supports the claim or thesis statement about similarities and differences.