What is the difference between managing stock by quantity and managing stock by value? | SAP-MM

 The transactions that make changes in the stock result in the stock updates and are recorded in the real time.
At any instance of time, the stock overview can be seen, which represents the current situation at a particular time.
That is the essence of the stock management by the quantity and applied to the following stock types:
=>    Located in the warehouse
=>    Ordered but not yet received
=>    Located in the warehouse and reserved for a particular purpose
=>    Reserved for Quality inspection
 The managing stock by value option prefers the qualitative review of the stock materials over the quantitative one. The valuation of stock is done either at the plant or at the location level.
The following updates are done in case of the stock managed by value of goods:
=>    The quantity and value for the goods movement
=>    The account that are assigned for cost accounting
=>    The G/L accounts for financial accounts with automatic assignment of account
=>    The valuation area in this concern is the organizational level at which the stock value is maintain It can be either at plant or storage level.