Answer:
Because it has a double division, it's like a double mitosis process
Step-by-step explanation:
As you can see in the image below, meiosis has a larger process than mitosis, and it results in 4 new cells. Actually, the first part of the process is very similar to mitosis, but the next part is the second division and thats the moment when new cells result just with half chromosomes.
In fact, meiosis is the reproduction process of sexual cells, and these cells need to have just half chromosome, because when a fetus is formed by an ovule and a spermatozoon (both of them just with half chromosomes) the genetic information is gonna be complete and not duplicated.