An array (sometimes vector or unidimensional table) is a row of more elements of the same type. Each element has an indice, which can be either an integer number or a character. A matrix (or bidimensional tables) is an array of arrays. This can be useful when dealing with number tables or even string tables. A block o variables (or tridimensional table is a array of arrays of arrays. This is rarely used but may sometimes be useful when defining shapes of 3D-objects. Pascal allows creation of 4-dimensional, 5-dimensional, 6-dimensional, etc. arrays but they are extremely rarely used.