Take a look around you. Everything you can see is made up of trillions of tiny units called cells. Cells are everywhere even though they are much too small for you to see without a microscope.
Eventually, cells will need to duplicate so that they can continue to grow and thrive. One of the main ways this happens is through a process called mitosis. Mitosis includes 5 phases: the prophase, the metaphase, the anaphase, the telophase, and the interphase.
In the prophase stage, a cell gets the idea that it is time for it to divide. The cell's DNA will be copied into a second strand as certain pieces, called the centrioles, get into the right place in order to prepare for the process of division.
Now all of the pieces are aligning themselves for the big split. The DNA lines up along a central axis and the centrioles send out specialized structures known as spindles to connect to the DNA. The DNA has now condensed into chromosomes. Two strands of a chromosome are connected at the center with something called a centromere.
The separation begins in this phase. Half of the chromosomes are pulled to one side of the cell; half go the other way. When the chromosomes get to the side of the cell, it's time to move on to telophase.
Now the division is finishing up. This is the time when the cell membrane closes in and splits the cell into two pieces. You will have two separate cells each with half of the original DNA.
The Interphase is the normal state of a cell. When it comes to cell division, you could call this the resting state. It's just going about its daily business of surviving and making sure it has all of the nutrients and energy it needs. It is also getting ready for another division that will happen one day. It is duplicating its nucleic acids, so when it's time for prophase again, all the pieces are there.
Once completing all of the five phases, the end result of mitosis will be two daughter diploid cells that are identical -- they both will have the same pieces and genetic code.