A school journal is actually a portfolio containing all your assignments, homework, projects, notes, and tests and exams taken for a class or subject.
Some people keep one large portfolio for all their classes and may provide smaller portfolios for classes that require it. Some keep a separate portfolio for every class. Each of these entries may be an assignment, a project, classwork or homework, and notes that are dated and stored in a binder.
Not everyone keeps a school journal because many of the times, after that class is taken you may throw away the notes, but once I used to keep a school journal. Inside of it was all my important paperwork for college as well as the course syllabus. There were notes and assignments in that journal as well as some projects that I kept while the teacher received a copy. Tests that I got back were also stored in this binder too. At the end of the semester, I would empty the binder and only keep the things that I thought I would need for life in general.
For example, I kept all the notes that I had for my French class because I want to learn French and there would come a day when these little phrases become important to me. I also kept work that I wrote in my English class such as analytical documents, narratives, and persuasive and informative pieces. The reason for this was because I worked on them. Projects and essays are the same thing. Notes, however, I threw away. I also threw away course syllabuses that were no longer required since I was no longer taking the class. Most of my exams I threw away too.
Some classes may require a portfolio. The teachers usually specify what they would like to see in these portfolios. I think that it is very important to know what goes into a school journal and one of the reasons why this is good is because it helps you to study more efficiently. Instead of having a notebook, you can have a portfolio where you store not only your notes but your assignments as well. You can easily look back in the portfolio and by seeing what you did and did not understand, you study better. While of course, many of the times you may have to turn in these journals at the end of the semester, you got good use out of them during it. A personal journal is not always a must, but it is a good thing to have.