A film review is an evaluative oral or written judgment about the quality of a movie, based upon various assumptions, facts, biases, etc. Professional film reviewers are known as critics; a film review usually includes a brief synopsis (avoiding spoilers, usually), a balanced notation of both the film's pros and cons, quotable wording, and some judgments. More extensive, in-depth film evaluations are called analytical essays.
An index is a specialized database that organizes information about the locations of articles in journals/magazines, reports and newspapers; and book chapters, papers in conference proceedings, and book reviews.
The best way to start searching for a review of a film in the following databases is to type the title of the work as a keyword, and add "review" to the search as another keyword. Searching this way is likely to exclude works that are not critical reviews of the film.