Dot

a . b or Dot[a, b] gives products of vectors, matrices, and tensors.

Examples

Vector dot product:

{1, 2, 3} . {4, 5, 6}
(* 32 *)

Matrix multiplication:

{{1, 2}, {3, 4}} . {{5, 6}, {7, 8}}
(* {{19, 22}, {43, 50}} *)

Please visit the official Wolfram Language Reference for more details.