According cell division; this essentially means it is

According to Hardin and Bertoni,1
a centrosome functions as a primary microtubule organizing center during cell
division; this essentially means it is the point of origin for all microtubules
associated thereof, as well as a source of securement2 so that the
microtubules can successfully move the chromosomes around as part of the cytoskeletal
mitotic spindle.2 The mitotic spindle is controlled by the two
centrosomes present at the spindle poles.3 However, at the end of
each cell cycle, each cell is left with just one centrosome, not two; the
second centrosome is “formed” at the end of the “Centrosome Duplication Cycle,”
a series of stages4 that involve the replication of the centrioles (structures
inside of the centrosome that are arranged at right angles to one another,5
as seen in figure 1) prior to the centrosome itself being fully duplicated.

Centrioles are important for cilia and flagellar purposes1, but also
responsible for the beginning centrosome duplication steps. Despite “centriole
splitting” (separation of the two parent centrioles within the centrosome left
from the last cell cycle4) being the first step of the centrosome
duplication cycle, there is concern about the timing of this event; therefore,
a centrosome is said to begin its visible duplication when a procentriole
(essentially a daughter centriole) forms/is assembled near the end of each of
its parent centriole.4 Holland, Lan, and Cleveland, have determined
that centriole duplication is reliant on the presence of Plk 4 (a type of
kinase that is useful in the regulation of centriole synthesis), and without
proper amounts of it, the centriole duplication will not proceed; nevertheless,
the group was unable to determine with certainty the specific point within the
cell cycle that it helps promote centriole duplication, only that it most
certainly does.7