Here's an extract from the BBC Business Editor Robert Peston. Notice the matter-of-fact way he takes it for granted that banks are financial intermediaries that borrow at one rate of interest and lend at a higher one, that they can only lend what they have got the funds for, and that their profits are squeezed if they find these harder to get:
One of the main reasons for this income squeeze is the rising cost for banks of borrowing money on wholesale markets, or from other financial institutions, at a time when what banks can charge for loans to customers remains under pressure - partly because central banks, and in its case the Bank of England, are keeping official rates at record lows, and partly because the demand for credit is subdued.
Lloyds is becoming less dependent on these less reliable wholesale sources of funding - as part of a strategic effort to make itself safer. And there has been considerable progress in that regard: its more dependable retail deposits represent 62% of all its funding today, compared with 56% a year ago.
But the price of wholesale funds is still a big influence on Lloyds' profits."