Coherence is best described as
the unity in a paragraph
the conclusive repetition in body paragraphs
the order of ideas enabling the reader to move easily from point to point.
the development of a major thesis

Coherence is best described as the order of ideas, enabling the reader to move easily from point to point. It is coherent when the words, phrases and sentences used are related, logical and supports the idea of the each line. The ideas are interconnected which would make the article or the paragraph smooth flowing and easily understood by the readers.