difference between Dataframe and class objects

Hi Marta! Thanks for reaching out. By definition, a class is a code template for creating objects. This means that you can define a class that will create a certain object for you when this class has been instantiated. Then, the DataFrame is a type of pandas object. Therefore, you can say there's the pandas DataFrame class, that is code template that can create a DataFrame for you. I agree that unless applied into practice, these terms may sound confusing but I am sure that if you do the relevant exercises, you will realise the distinction can become quite obvious. Hope this helps.
Best,
Martin