Generally translated as "main element", when doing an algorithm on a matrix, the first part of the element is carried out. This is common in simplex method of linear programming.

Wiki is explained as follows:

Pivot element

(The first element in the trapezoidal matrix that is different from zero)

Pivot or pivot elements are elements of matrix, which are first selected by algorithms (such as Gaussian elimination, quick sorting and simplex algorithm) to perform some calculations with matrix.

The matrix algorithm mentioned above needs an entrance with a pivot position different from zero to work normally or not at all. According to the algorithm, choose a non-zero (random) element or an element with the largest absolute value in a row or column. This is the so-called pivoting. Rows containing perspective elements are called perspective rows, and columns of perspective elements are called perspective columns.

The Pivot element in quick sort refers to the element selected as the partition boundary. Quick sort sorts all elements? Left "and? Right "cycle.