null matrix

A zero matrix is an m×n matrix consisting of all 0s, denoted 0. Zero matrices are sometimes also known as null matrices. A zero matrix is the additive identity of the additive group of m×n matrices. The matrix exponential of 0 is given by the identity matrix I. An m×n zero matrix can be generated in the Wolfram Language as ConstantArray[0, {m, n}].

identity matrix | unit matrix