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. means "adividesb").
In mathematics, double vertical bars are also used to refer to various mathematical concepts. These include the parallel relation (as in ) and the norm of a vector (as in ).