A major use of zinc is for galvanizing steel, such as sheet steel used in cars. The steel is coated quth zinc for corrosion protection.
"Galvanizing" is a term used to nean any zinc coating process. This is commonly done by passing the steel through a bath if molten zinc (hot dip galvanizing) or through electrolysis (electrogalvanizing).
The corrosion protection comes from the fact that zinc is oxidized at a lower potential than iron, the zinc is more reactive. Thus when the steel is coated with zinc, the zinc corrodes instead of the steel, even where some steel might be exposed by (for example) cutting or scratching the steel.
This is only a very brief explanation, the reader is referred to https://en.wikipedia.org/wiki/Galvanization.