How do both the parent and the offspring cells have the same amount of DNA if the parent cell was divided in two?

Interphase (a stage of mitosis) takes the cells DNA and creates a copy of it. Through prophase, metaphase, anaphase, and telophase the cell will split apart. Then you get it so each daughter cell has the exact same DNA as the parent, including the amount it had. Meiosis is kind of the same way but you have two sets of DNA to choose from. The genes get combined and that's where you get dominant and recessive traits. Say your mom had brown hair and your dad had blonde hair. You would have the genetics you either have brown or blonde hair. Say you get blonde hair and you marry a redhead. Your children have a more likely chance to get blonde or red hair, but there is a possibility to have brown hair. It is all probability on how you guess what meiosis will yield. Hopefully this isn't too confusing:)