Think of a paragraph or an essay as a jigsaw puzzle. All of the pieces in a puzzle go together to make one picture or idea. A paragraph or essay is the same. In a paragraph, the examples and analysis of the topic sentence fit together into a coherent whole about one subject. The paragraphs in an essay all support the essay’s thesis statement to make a coherent and complete essay. A paragraph is focused on one subject; if you change subjects, you must start a new paragraph. An essay is the same, only you have several examples to support your thesis. In the end they must cohesively address the essay’s main idea established in the thesis.
If you connect ideas, thoughts, and explanations into one work, whether it is a paragraph or essay, you are communicating your ideas effectively and coherently.