Analysis is the intellectual process of breaking something (a text, data set, situation, etc.) down into smaller parts for the purpose of understanding it better.
An analytical essay is a type of informative essay that analyzes parts of an item (text, data set, situation, etc.) and explains their meaning, purpose, or result in relation to the whole.
A definition essay is a type of informative essay that explains the meaning of a complicated word or concept or alters—by complicating, adding to, or otherwise changing—the standard definition of a word or concept.