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.
And Why it is Essential for a Retail Business. POS or PoS is an abbreviation for Point of Sale (or Point-of-Sale, or Point of Service). The term is applicable to a retail shop or store, the checkout/cashier counter in the store, or a location where such transactions can occur in this type of environment.POS, short for OLE for Point of Sale, was the first commonly adopted standard and was initiated by Microsoft, NCR Corporation, Epson and Fujitsu-ICL. OPOS is a COM-based interface compatible with all COM-enabled programming languages for Microsoft Windows.