The field of use of matrices is wide.
Math is one field where matrices are very useful. For instance, matrices are very useful in solving linear systems, whose number of equations and variables is large. The elements located on the rows of the matrices represents the coefficients of the variables involved in the equations of the system. The number of rows of a matrix is equal to the number of equations and the number of columns of a matrix tells us how many variables are involved in the equations of the system. We usually start to solve systems that involves two equations and two variables. If the equations of the system are more than two and if the number of variables is larger than two, we'll need to use matrices to solve the system, if it's possible.
We can also use matrices to represent complex numbers.
The matrices are useful in engineering (finite element method, mesh analysis), architecture, geology and statistics.
The bidimensional image we can see on the computer screen is the projection of a tri-dimensional image and this projection is possible due to matrices.
Matrice reffer to numbers arranged in rows by columns enclosed in brackets.