a vertical bar is the glyph "|". it has several other names besides vertical bar, such as "pipe", "vertical slash", and "bar". in mathematics, it may be put on both sides of a real or complex number to mean its absolute value. when applied on both sides of a matrix, it means its determinant. when placed in between two numbers, it means the divisibility relation (for example. formula_1 means ""a" divides "b"").