A more thorough explanation:

Definition: Extraneous means something that is not necessary or relevant to the situation. It is similar to the word extrinsic, which means coming from the outside. Example: During a math test, a student starts talking about their weekend plans. This conversation is extraneous because it is not related to the test and does not help the student or anyone else in the class. Example: A chef adds an extraneous ingredient to a recipe, which changes the taste and texture of the dish. This ingredient is not necessary and may even ruin the dish. These examples illustrate how something extraneous is not needed or helpful in a particular situation. In the first example, the student's conversation is distracting and does not contribute to their success on the test. In the second example, the chef's addition of an unnecessary ingredient changes the dish in a negative way.