General / Off-Topic What's a "Repo Rate" ?

[Robin of Spiritwood]

There's suddenly a whole lot of alerts about this thing, and I don't understand why it's important, or how it works.
If anybody here is informed or works in the area, can you explain it?

 

[Caramel Clown]

From Google:

repo rate

. The discount rate at which a central bank repurchases government securities from the commercial banks, depending on the level of money supply it decides to maintain in the country's monetary system. ... Repo is short for repossession.

Bunch of corporate banker talk here, I still have no clue what is it.