user132728: So I'm researching SegWit, and as far as I'm aware, it re-organizes the data structure of transactions so that the ECDSA signature is not included in the preimage of the Tx Hash.
I am also aware that it doesn't even store the ECDSA on the blockchain. But where is it even stored then and how do nodes check for the signature when validating transactions?
Additionally, why does SegWit incorporate new address formats? I can't seem to understand how this would relate to changing the Tx Structure by moving the EDCSA's somewhere else.
All answers appreciated.

user5406: Addresses are shorthand for output scripts, and instruct senders how to lock funds for the recipient. Since segwit outputs use different output scripts than non-segwit outputs, we need a different shorthand for them.
For segwit transactions, the signature data is part of the witness section of the transaction.  The witness is part of the transaction and the whole transaction gets written to the blockchain. While the witness is not used to calculate the txid, it is part of the "witness txid" which is generated from the whole transaction. The latter is used to construct the witness commitment in the coinbase transaction which ensures that witnesses are immutable after a transaction is confirmed.

132728: <p>So I'm researching SegWit, and as far as I'm aware, it re-organizes the data structure of transactions so that the ECDSA signature is not included in the preimage of the Tx Hash.</p>
<p>I am also aware that it doesn't even store the ECDSA on the blockchain. But where is it even stored then and how do nodes check for the signature when validating transactions?</p>
<p>Additionally, why does SegWit incorporate new address formats? I can't seem to understand how this would relate to changing the Tx Structure by moving the EDCSA's somewhere else.</p>
<p>All answers appreciated.</p>
 5406: <p>Addresses are shorthand for output scripts, and instruct senders how to lock funds for the recipient. Since segwit outputs use different output scripts than non-segwit outputs, we need a different shorthand for them.</p>
<p>For segwit transactions, the signature data is part of the witness section of the transaction.  The witness is part of the transaction and the whole transaction gets written to the blockchain. While the witness is not used to calculate the txid, it is part of the &quot;witness txid&quot; which is generated from the whole transaction. The latter is used to construct the witness commitment in the coinbase transaction which ensures that witnesses are immutable after a transaction is confirmed.</p>
