An essay is usually written in response to a question or proposition. The essays are generally written in an educational and analytical tone. . It discusses both the arguments in favor and against of the topic. The essays usually do not need any formal format and no headings and sub-headings are used.
The purpose of an paper is to inform the readers of a concept. The paper are written in a conversational tone so as to inform the readers of a concept in an interesting manner. The paper however usually follow a heading and sub-headings format to make readers understand the concept easily.
The purpose of a journal is to record the development of an idea as it comes to the writer’s mind. The journals are however written in an informal tone as a discussion or process of learning mostly chronologically. In case of journals, there may or may not be the use of headings and sub-headings format.