Think of oxidation like a generous person giving away their money (electrons) to someone else, resulting in them having fewer electrons/higher relative charge.

OIL RIG (Oxidation Is Loss, Reduction Is Gain of electrons)

In this single displacement reaction, metallic zinc ($\text{Zn}$) is more reactive than copper ($\text{Cu}$). Zinc displaces copper from copper sulfate ($\text{CuSO}_4$) solution by losing two electrons to form zinc ions ($\text{Zn}^{2+}$), while copper ions ($\text{Cu}^{2+}$) accept those electrons to form solid copper metal.

Always remember the phrase 'LEO says GER' (Lose Electrons = Oxidation, Gain Electrons = Reduction) to quickly solve redox and electrochemistry questions in competitive exams.