"Non" is a prefix derived from Latin, meaning "not" or "without." It is commonly used in English to negate a word, indicating the absence of something. For example, in the word nonexistent, it signifies that something does not exist. In various contexts, "non" can also refer to categories or classifications that exclude certain elements. For instance, non-profit organizations operate without the primary goal of making a profit. This prefix helps clarify the nature of an entity or concept by highlighting what it is not.