what does ".matrix" do in java code example

Example: java matrix

int [ ] [ ] scores = {   { 20, 18, 22, 20, 16 },
                                 { 18, 20, 18, 21, 20 },
                                 { 16, 18, 16, 20, 24 },
                                 {  25, 24, 22, 24, 25 }
                             };