Mitosis is asexual reproduction of a parent cell to create two identical daughter cells (assuming there are no errors.)
Meiosis is a specialized cell division which results in gametes. These specialized cells are used for reproduction of multi-cellular organisms. They contain only half of the genetic material. These cells are haploid meaning they only contain one copy of each chromosome instead of the usual 2 copies found on the diploid parent cell. This makes them genetically different from the parent cell. They also go through a process called crossing over, which further alters their genetic makeup. This is advantageous because it allows for more genetically diverse combinations in future generations. Each gamete is different which is the source of diversity in future generations when fertilization merges the genetic material from two haploid cells to create a diploid zygote and ultimately a genetically unique organism.