...
It's common for organizations to have duplicate information on different systems. For example, customer information could be stored in both a CRM and accounting system:
While some data in both systems is identical, some is similar but not the same.
With small organizations, there usually isn't an issue keeping just a few systems up to date. The process of keeping data up to date between disparate systems is called Data Integration or DI.
As organizations bring more and more systems online, their business data is duplicated even further and the problem of keeping all of the systems up to date becomes problematic. For example, imagine a delivery service that stores information about its customers in several systems:
As information about their customers change, the difficulty of keeping all the systems up to date becomes exponentially more difficult as the number of systems increases.
...