Answer:
Analysis is when an author explains why a particular piece of evidence in an essay is important to the topic.
Explanation:
In an essay, the reader can analyze theme, motivation, compositions of the work, character... All the parts of the essay can be part of an analysis.
When a reader reads the essay, he/she could notice why the author emphasizes a particular piece of evidence and its importance for the essay. In an essay, the author will need to explain and use some type of argument to support his/her opinion and explanation. The author can analyze an idea, an issue and support them with a piece of evidence so the reader can have better insight.