Mac Dictionary defines it as:
make or become different : [ trans. ] a proposal to change the law | [ intrans. ] a Virginia creeper just beginning to change from green to gold.
• make or become a different substance entirely; transform : [ trans. ] filters change the ammonia into nitrate [ intrans. ] computer graphics can show cars changing into cheetahs.
• [ intrans. ] alter in terms of : the ferns began to change shape.
• [ intrans. ] (of traffic lights) move from one color of signal to another.
• (of a boy’s voice) become deeper with the onset of puberty.
• [ intrans. ] (of the moon) arrive at a fresh phase; become new.
2 [ trans. ] take or use another instead of : she decided to change her name.
• move from one to another : she changed jobs incessantly | change sides.
• exchange; trade : the sun and moon changed places.
• [ intrans. ] move to a different train, airplane, or subway line.
• give up (something) in exchange for something else : we changed the shades for vertical blinds.
• remove (something dirty or faulty) and replace it with another of the same kind : change a light bulb.
• put a clean diaper on (a baby or young child).
• engage a different gear in a motor vehicle : [ trans. ] wait for a gap and then change gears | figurative with business concluded, the convention changes gear and a gigantic circus takes over the town.
• exchange (a sum of money) for the same amount in smaller denominations or in coins, or for different currency.
• [ intrans. ] put different clothes on : he changed for dinner.
1 the act or instance of making or becoming different : the change from a nomadic to an agricultural society | environmental change.
• the substitution of one thing for another : a change of venue.
• an alteration or modification : a change came over Eddie’s face.
• a new or refreshingly different experience : couscous makes an interesting change from rice.
• [in sing. ] a clean garment or garments as a replacement for clothes one is wearing : a change of socks.
• ( the change or the change of life) informal menopause.
• the moon’s arrival at a fresh phase, typically at the new moon.
• Baseball another term for change-up .
2 coins as opposed to paper currency : a handful of loose change.
• money given in exchange for the same amount in larger denominations.
• money returned to someone as the balance of the amount paid for something : I watched him pocket the change.
3 (usu. changes) an order in which a peal of bells can be rung.
4 ( Change or ‘Change) Brit., historical a place where merchants met to do business.
change color blanch or flush.
change hands (of a business or building) pass to a different owner. • (of money or a marketable commodity) pass to another person during a business transaction : no money has changed hands.
change one’s mind adopt a different opinion or plan.
change off take turns.
a change of heart a move to a different opinion or attitude.
change step (in marching) alter one’s step so that the opposite leg marks time.
change the subject begin talking about something different, esp. to avoid embarrassment or the divulgence of confidences.
change one’s tune 1 express a different opinion or behave in a different way. 2 change one’s style of language or manner, esp. from an insolent to a respectful tone.
for a change contrary to how things usually happen; for variety : it’s nice to be pampered for a change.
ring the changes vary the ways of expressing, arranging, or doing something. [ORIGIN: with allusion to bell-ringing and the different orders in which a peal of bells may be rung.]
change over move from one system or situation to another : crop farmers have to change over to dairy farming.
Sometimes we all need change in our lives.