An improper fraction is a fraction where the numerator is greater than the denominator
This is improper because you can't have more parts than the whole. WELL you can, math is confusing
You can have a mixed number, which says how many wholes there are and how many parts of a whole there is.
It's just called an improper fraction just like that I guess,
all you really need to know is that the numerator (the top number) is greater than the denominator (the bottom number), and to make it proper, you have to make it into a mixed number, but you have to use improper fractions to perform some operations.
You'll learn more about converting stuff from improper fractions to mixed numbers and vice versa to perform certain operations in the future, but for now, you just need to know what an improper fraction is.
I hope this helped, let me know if you have any questions.