What is the Catch on Land Auctions

[Pradeep Saraf]

Hi , I am new to real estate and still exploring the resources.

my q is - What is catch with the Land Auctions(example - land liquidation auctions). What are the details that we need to be aware of making those purchases if we happened to be the winning bidder. The prices of some parcels are too good to be true which makes me believe how authentic the lands are and what are the list of documents I need to check from county to proceed further with the purchase. appreciate the input. 

Thank you!