I have a question in college accounting. Does this say that income is deferred but revenues/expenses aren't?

" Under the installment-sales method of accounting, companies defer income recognition until the period of cash collection. They recognize both revenues and costs of sales in the period of sale, but defer the related gross profit to those periods in which they collect cash. Thus, instead of deferring the sale, along with related costs and expenses, to the future periods of anticipated collection, the company defers only the proportional gross profit. This approach is equivalent to deferring both sales and costs of sales. Other expenses--that is, selling expense, administrative expense, and so on--are not deferred."