A journal or a log is about your personal journey, you decide the topic, and you decide what you want to put in it.

I generally just 'log' my books on an app, I used GoodReads for several years and just switched to StoryGraph this year. I log everything that I finish reading no matter the length or the format. Others are free to exclude what doesn't fit their criteria or add books that were DNF.

I also have a couple of reading journals. One is dedicated to series, I use this to keep track of which books I've read and to list all the books in the series in order so I don't have to keep looking it up when I need the next book.

My other journal is for a long-term project of reading books by authors from 195 countries, I plan to read fiction and nonfiction from each country. This is more of a traditional journal, where I'll write about my process of researching and finding the books as well as my impressions of the nation from the books that I've read.

I love to join challenges, there are thousands available in a variety of places. This is one of the features I love on StoryGraph. You can search for challenges in a dozen categories, and when you log a book to complete a prompt, it will show your progress in the challenge. You can see which books you've logged for each prompt and which books others have logged for each prompt.