A Chainstamp Proof is a way to show a digital file existed at a certain point in time. A timestamp. We submit transactions to the bitcoin blockchain and a part of each transaction contains data derived from files submitted on our website. This blockchain data then provides an unalterable anchor point in time, and because the blockchain can never be changed, the proof exits forever and is easy to verify.
The process of verifiying a Chainstamp proof includes 1) an original file 2) our website or a "proof file" that you've downloaded from us and 3) the bitcoin blockchain (which can be viewed on various websites or can be downloaded to your own system).
A proof file can be downloaded once a chainstamp proof is in a submitted or confirmed state. It let's you prove the existance of your original files using the blockchain and can be used even if our service is no longer around.
Warning this is pretty technical
Your original file is hashed and that hash is put into the proof file. The proof file is hashed and put into the bitcoin blockchain as part of a transaction that gets put inside a block. Finding the timestamp of the block that contains the transaction (which contains your proof file hash) proves the existence of your original file (whose hash is inside the proof file) and provides a verifable timestamp.
The above steps are technical and are meant only to be used when our service is not available or if you want independent verification.