Fractional-reserve banking is the banking practice in which banks keep only a fraction of their deposits in reserve (as cash and other highly liquid assets) and lend out the remainder, while maintaining the simultaneous obligation to redeem all these deposits upon demand. Fractional reserve banking necessarily occurs when banks lend out any fraction of the funds received from demand deposits. This practice is universal in modern banking.
By its nature, the practice of fractional reserve banking expands money supply (cash and demand deposits) beyond what it would otherwise be. Because of the prevalence of fractional reserve banking, the broad money supply of most countries is a multiple larger than the amount of base money created by the country's central bank. That multiple (called the money multiplier) is determined by the reserve requirement or other financial ratio requirements imposed by financial regulators.
For an individual bank, the deposit is considered a liability whereas the loan it gives out and the reserves are considered assets. The deposit will always be equal to the loan plus the reserve, since the loan and reserve are created from the deposit. This is the basis for a bank's balance sheet.
The creation and destruction of commercial bank money occurs through this process. Whether it is created or destroyed depends on what direction the process moves. When loans are given out, the process moves from the top down and money is created. When loans are paid back, the process moves from the bottom to the top and commercial bank money is canceled out, effectively erasing it from existence.
Do some research and stop talking bollox.