There is a lack of consensus on the distinction between lingual taxa such as languages and dialects. A neutral term in linguistics is "language variety" (a.k.a. "lect"), which can be anything from a language or a family of languages to a dialect or a continuum of dialects, and beyond. The most common, and most purely linguistic, criterion is that of mutual intelligibility: two varieties are said to be dialects of the same language if being a speaker of one variety confers sufficient knowledge to understand and be understood by a speaker of the other; otherwise, they are said to be different languages.