change

(noun): The process of becoming different.
(noun): Small denominations of money given in exchange for a larger denomination.
(noun): A replacement, e.g. a change of clothes
(noun): Balance of money returned from the sum paid after deducting the price of a purchase.
(noun): Usually coins (as opposed to paper money), but sometimes inclusive of paper money
(noun): A transfer between vehicles.
(noun): A change-up pitch.
(noun): (campanology) Any order in which a number of bells are struck, other than that of the diatonic scale.
(noun): A place where merchants and others meet to transact business; an exchange.
(noun): A public house; an alehouse.
(verb): To become something different.
(verb): To make something into something else.
(verb): To replace.
(verb): To replace one's clothing.
(verb): To replace the clothing of (the one wearing it).
(verb): To transfer to another vehicle (train, bus, etc.)
(verb): To exchange.
(verb): To change hand while riding (a horse).

The product is undergoing a change in order to improve it.
Can I get change for this $100 bill please?
A customer who pays with a 10-pound note for a £9 item receives one pound in change.
Do you have any change on you? I need to make a phone call.
The train journey from Bristol to Nottingham includes a change at Birmingham.