It
is an annual. A perennial doesn't die every year. I think that's what you meant though
A cannabis plant however, if grown indoors, can live for years. It just needs a constant veg cycle, or to be re-vegitated after harvest. If the soil is kept properly the plant will not die and continue to grow in your closet until you decide to let it autumn off and die, or to cut it down. However this generally isn't done with such tall plants.