We refer to the procedure through which cells multiply and divide into two new cells as the cell cycle. G1, S, G2, and M are the phases of the cell cycle, respectively.
The detailed information is available on google. But to summarize….
The phase of cell cycle is none other than a stage of cell cycle consisting of a four-stage process that occurs as an ordered sequence of events in a cell in preparation for cell division. The cell cycle is therefore a four-stage process in which the cell increases in size (gap 1, or G1 phase), copies its DNA (synthesis, or S phase), prepares to divide (gap 2, or G2 phase), and divides (mitosis, or M).
The stages namely, G1, S, and G2 make up interphase, which accounts for the span between cell divisions. On the basis of the stimulatory and inhibitory messages that a cell receives, it decides whether it should enter the cell cycle and divide.
Please note: The cell cycle is a cycle, rather than a linear pathway, because at the end of each go-round, the two daughter cells can start the exact same process over again from the beginning.