Definition:Modulus


 * The absolute value $\left|{x}\right|$ of a real number $x$.


 * Modulus of Complex Number: the length of a complex number when drawn as a vector on the complex plane.


 * Modulus of Complex-Valued Function: The real-valued function $\left|{f}\right|$ obtained by taking the (complex) modulus of all the values of the complex-valued function $f$.


 * Modulus (Geometric Function Theory): The term modulus is used to denote certain conformal invariants of configurations or curve families.


 * Congruence (Number Theory): where $x \equiv y \pmod z$, $z$ is the modulus.


 * Modulus of a Multiindex: The modulus of a multiindex $k = \left \langle {k_j}\right \rangle_{j \in J}$ is defined by $\displaystyle |k| = \sum_{j \in J}k_j$