Cell division is a process which splits a parent cell into two or more daughter cells. Cell division is important in DNA replication. In eukaryotes, the cell division involved is called mitosis whereas it is known as binary fission in prokaryotes. In some cases, cell division is involved in asexual reproduction.
One of the most basic functions of life is cell division. The whole purpose of cell division is get a complete set of the original cells DNA into each of the two new daughter cells. Now why would a cell do that? Primarily reason is for growth and reproduction, for reproduction purposes or just think about how a bacteria goes and makes babies. It does it by dividing and making two cells from the original one. You used to be a single cell a long, long time ago when your mum and your daddy shook hands and somehow they created a single cell, you're about a trillion cells now and how did you get so many cells now by doing cell division over and over gazillions of times.
You also do cell division all the time you're doing it right now why? Well all day long you're kind of scratching, crowing at yourself knocking off skin cells, they drift down on a nice light blizzard of dead skin cells and wind up underneath your bed as dust. Well, how do you get replacement skin cells so you can keep scratching at your dandruff? Well by doing cell division, there's 3 forms of cell division or 3 processes for bacteria though do a process known as binary fission, whereas eukaryotes their standard way of doing cell divisions called mitosis there's a specialized version of cell divisions for eukaryotes called meosis but that's only used for sexual reproduction. If we take a quick look at this, you can see just by looking at them the 3 processes are different binary fission you start off with a single cell where that has one molecule of DNA you copy it and then you divide it into the two new daughter cells pretty quick and easy.
Whereas with mitosis you start off with one cell and you have lots of molecules of DNA in this example there's 4 different molecules of DNA by the end of mitosis you wind up with two new daughter cells each with again 4 molecules of DNA. Here we have meosis on the other hand where again you start off with 4 DNA molecules but the 4 daughter cells only have 2 chromosomes each. And there you go, that's cell division and as you can see it's all about getting the DNA into the new daughter cells.