What Does As Is, Short Sale, Subject To Third Party Approval Mean In Real Estate?

"As is" means the seller is unwilling to make any repairs.  What you see is what you're buying.  There are some things they may HAVE to repair but it depends on a few things.  

"short sale" means the loan(s) on the property are more than the value of the home and the seller is not going to put money in to pay off the loan amount above the sale price.  So, they're asking the bank to take less than the loan amount to pay off the loan as part of the sale.

"Subject to third party approval" means, in the case of the short sale, that the seller can't say "yes' to your offer without the banks approval.  This is because of the above - they're asking the bank to take less than the full amount of the loan to pay it off.