A personal log is usually more structured and focused on recording specific activities events habits goals or progress. A journal is more personal and expressive and is often used to write about thoughts feelings experiences and reflections.
In simple terms personal logs track what you do while journals explore what you think and feel.
A personal log is usually created to keep useful records while a journal is often created for personal reflection and self expression.
A journal gives you more freedom because you can write about anything that is on your mind while a personal log usually follows a specific purpose.
If you want a simple record of your daily activities choose a personal log
If you want a place to express thoughts and feelings choose a journal.
There is no strict rule that separates them because people can use both in similar ways
The important difference is that logs usually emphasize tracking while journals usually emphasize reflection.
Logs are often easier to scan later because they contain organized information while journals can require more reading because they contain personal reflections.
A personal log might contain checklists numbers times and achievements while a journal can contain stories observations questions emotions and lessons.
I would use a personal log to remember what I accomplished and a journal to understand why certain experiences affected me.
The difference is mainly structure
Personal logs tend to follow a consistent format while journals can change depending on what you want to write about.
If your goal is productivity tracking then a personal log is probably better
If your goal is self reflection then a journal may be more helpful
You could use a personal log to record how many hours you studied each day while a journal could explain how you felt about your studies and what you learned from the experience