The single source of truth, explained
When the same fact lives in five places, all five eventually disagree. A single source of truth is the cure for a whole class of problems.
A customer’s address is in the CRM, the billing system, the shipping tool, and a spreadsheet. They were all correct once. Now they disagree, and nobody knows which is right. This is the problem a single source of truth solves.
Copies drift
The moment a fact is copied, the copies start drifting apart. One gets updated, the others don’t. Over time you accumulate contradictory versions and spend real effort reconciling them, or worse, acting on the wrong one.
One home, many windows
The fix isn’t fewer tools. It’s deciding which system owns each fact, and having every other tool read from it rather than keep its own copy. The data lives in one place; everything else is a window onto it. Update once, correct everywhere.
If a fact lives in five systems, you don’t have five backups. You have five future arguments.