Matrix multiplication in C programming involves multiplying two matrices, represented as two-dimensional arrays, and storing the result in a third array. The multiplication process requires multiplying each element in a row of the first matrix by each element in a column of the second matrix and summing the products to find the corresponding element in the result matrix. Specifically, for matrices A (m x n) and B (n x p), the resulting matrix C will have dimensions m x p. The implementation typically uses nested loops to iterate through the rows of matrix A and the columns of matrix B, with an additional loop for the element-wise multiplication and summation. Understanding this process is crucial for correctly implementing matrix multiplication in C.