Here's why:

* Cell division: The process of creating new cells is called cell division.

* Cell death: Cells naturally die off through a process called apoptosis.

* Balance: Normally, there's a balance between cell division and cell death, keeping tissues and organs healthy.

* Growth: When cell division outpaces cell death, the overall number of cells increases, leading to growth in size or volume of tissues and organs.

This process is essential for:

* Development: During embryonic development, rapid cell division leads to the formation of all the body's tissues and organs.

* Repair: When we get injured, cell division helps to repair damaged tissues.

* Normal growth: Throughout our lives, some cells continue to divide, contributing to the growth and maintenance of our bodies.

However, if this balance is disrupted, it can lead to problems like:

* Cancer: Uncontrolled cell division can lead to the formation of tumors.

* Developmental abnormalities: Problems with cell division during development can cause birth defects.