Salesforce: What is Multi-currency?

Salesforce Multi-Currency feature is useful for an international organization where different currencies can be made available in one single organisation.

Note: Once this is enabled, it cannot be turned off

Below is an example of how WDCi as a company uses multi-currency:

WDCi HQ in Australia uses AUD
WDCi Branch in Malaysia uses MYR

So how does multi-currency work?

Multi-currency will automatically choose and display the currency based on the user’s personal information. ( User Name | Setup | Personal Information)

When the currency is defined in the user’s personal information, Related objects will inherit the currency. For example, Account, Contacts, Opportunity or even products will be using MYR – Malaysian Ringgit.