Do I need a guarantor to study in Australia?

I have asked teachers who have experience in studying in Australia and mentioned that studying in Australia requires one year's tuition in advance, and applicants also need to prove that they have the financial ability to pay all the expenses during their stay in Australia. If the applicant can prove that he has enough funds, he doesn't need a financial guarantor. If the applicant has no funds, he needs an economic guarantor. Teacher Liu, who is studying online, also said that the guarantor can be a relative or friend of the applicant, but it is best to be a relative of the applicant. The nationality of the guarantor is not limited, and some institutions can also act as guarantors.