Alpha Centauri is our nearest star system. This was located 4.37 light-years away from our earth. If our fastest spaceship starts traveling towards this star then it will take 70,000+ years to reach there.
So in order to get there quickly, Project Starshot was announced in the year 2016.
This project involves installing ground base light beamer. That will use a very strong beam of light and push the nanocrafts towards this star with a speed of up to 100 million miles per and hour.
If our nanocraft reaches 20% speed of light, then it would reach there easily in less than 20 years.