The cell cycle is a series of events, that happen within a cell, that ultimately lead to it's duplication and division. These cells develop into a "mature" organism, that is a part of a process of which the cells are "renewed". Such is the process in hair, skin and blood cells. The starting cell, by the end of the process, becomes two individual cells.
The Interphase is the beginning of the process, and it has three sub-phases.
G1 is the first phase, and the cell grows in size. This phase is to primarily ensure that everything is ready to begin DNA synthesis.
The S(ynthesis) phase is when the cell replicates the DNA.
The final sub-phase, is the G2 phase. The cell grows in size again, and much like the G1 phase, it primarily ensures that everything is ready to begin DNA synthesis.
After the Interphase has finished, the Mitosis phase begins for the cell.
Cell growth stops at this stage, and the cell focuses on it's division into two daughter cells. Another 'check' happens, to ensure that everything is ready to begin DNA synthesis.
The chromosomes are divided between the daughter cells, of which become genetically identical cells.