In a reaction, what is the term used for the species that gets oxidized?

In a chemical reaction, the species that gets oxidized is referred to as the reducing agent. Oxidation involves the loss of electrons, and as this species loses electrons, it facilitates the reduction of another species by providing those electrons. The reducing agent is crucial to the reaction because it donates electrons to another species (the oxidizing agent), which undergoes reduction.

For clarity, the oxidizing agent is the species that gains electrons and is reduced itself, while a catalyst is a substance that speeds up the reaction without being consumed, and a reactant is any substance that undergoes a change during the reaction. In this context, the reducing agent's role in the electron transfer process is essential for recognizing how oxidation and reduction occur.