"Short Sale, Subject to bank approval..."

[John Romero]

Hi Everyone,

I'm really considering a cash-flow property, (To hold for an extended time period while collecting rent)

It's on the MLS and has been there for a while; The property recently expired and has appeared once again with a price reduction. It has this clause at the end "Short sale, subject to bank approval".

What does this mean? Are there any good strategies to make an offer on a property such as this?

Thanks!!