One difference is the release dates. LEGO Harry Potter Years 1-4 was released on June 26, 2010, while Creator Chamber of Secrets was released on August 1, 2002.
Another difference is the number of sets that were released. LEGO Harry Potter Years 1-4 had 16 sets, while Creator Chamber of Secrets had only 4.
The sets from LEGO Harry Potter Years 1-4 were typically larger and more complex than Creator Chamber of Secrets sets, and they included a wider range of minifigures.
Creator Chamber of Secrets sets focused specifically on the events of the movie "Harry Potter and the Chamber of Secrets", while LEGO Harry Potter Years 1-4 included sets based on the first four Harry Potter books.
Overall, LEGO Harry Potter Years 1-4 was a larger, more comprehensive series that provided a wider range of sets based on the first four Harry Potter books, while Creator Chamber of Secrets focused specifically on one of the movies.