"cash" in your pocket is central bank money. Current president keeps the dead presidents good (in theory). In the bank it is merely a promise of money.

Cash can (arguably) mean paper money but there is often a distinction made in capital markets - physical cash is for retail banks.

An applied example of a cash position in finance is repo: You need some short term cash - a simple hack financial markets use to do this in an administrative/credit efficient way is to simply sell (say) a bond (the collateral), receive some money (your cash), then agree to buy the bond back tomorrow for slightly more than you sold it for (the interest rate).