I wouldn't worry about waterfalls @NaanPeshwari . I'm a finance person and despise them.
Haven't seen if someone has explained prepayments to you, but they're pretty straight forward.
If you pay 12 months rent in advance that's a prepayment because you have paid the expenditure upfront, at the beginning of the period it relates to.
As many people noted above, financial reporting looks at monthly costs to businesses. If you prepay, that full cost will show in one month and make the figures look really wrong as they are too high.
Using my example of 12 months rent in advance paid 1 September. Assume rent is £1000 per month, 12 months would be a £12000 prepayment. So, if you just reported the cash spend, you would have 12000 in September. But that payment is for September 2025 to August 2026. Instead, the rent is recognised as a monthly cost of 1000 for rent over the 12 months. Rent cost after 3 months is 3000 and the value of the prepayment is 9000.
So it's sort of like 2 buckets. At the beginning everything is in the prepayment bucket. As the year moves on, every month the cost of rent (1000) moves from the prepayment bucket to the rent bucket. By the end of the 12 months the prepayment bucket will be empty ie Nil and the rent bucket will be full ie 12000.
Prepayments show on the Balance Sheet (Statement of Financial Position) as an asset as they have future benefit to the company. That's where the bank account balance also sits as well as debtors (people who owe you money), creditors (people you owe money), employee payments owing, assets like cars, buildings, equipment, land etc
Rent shows on the Profit and Loss (Statement of Financial Performance) as it is an expense that is taken into account to calculate the profit of the company for the relevant period.