The most obvious difference between 2D and 3D is in the name
2D means two-dimensional and 3D means three-dimensional. In other words, a 2D animation has flat images that lack depth and can only move vertically and horizontally.
Your 2D animated film
A 2D animated movie is well suited for explaining how something works, such as an organization or service. One advantage is the ability to insert completely different objects to explain things.
Another benefit with animated film is that it can have a long life. In a filmed movie, there may be machines that gets old or personnel who have been replaced.
With an animated film, it is also easier to make a film that is lighter and with a bit of humor. Then it becomes easier to get the viewer to stay there to take part in the whole message.