Mixed and Absolute Cell References. To avoid this problem created by the relative cell reference A7, mixed and absolute cell references can be used, which prevent all or part of a cell reference in a formula from changing as it is copied. Absolute and mixed cell references are created by adding dollar signs ($) to a cell reference. For example, in the image above, the cell reference $A$6 in the formula in cell B2 is an absolute cell reference and $A2 is a mixed cell reference.
The point of sale (POS) is the time and place where a retail transaction is completed. It is the point at which a customer makes a payment to the merchant in exchange for goods or after provision of a service.
A passive optical network (PON) is a telecommunications network that uses point-to-multipoint fiber to the end-points in which unpowered optical splitters are used to enable a single optical fiber to serve multiple end-points.wo major standard groups, the Institute of Electrical and Electronics Engineers (IEEE) and the Telecommunication Standardization Sector of the International Telecommunication Union (ITU-T), develop standards along with a number of other industry organizations.