Reading Bitcoin Raw Transaction

Reading Bitcoin Raw Transaction

I want to understand Bitcoin data structure. So i try to understand a raw transaction in json format. When i checked the API documentation of https://blockchain.info (http://ift.tt/LTbJ0J), i see that input structure is defined for transactions like this:

"prev_out":
{
    "hash":"a3e2bcc9a5f776112497a32b05f4b9e5b2405ed9",
    "value":"100000000",
    "tx_index":"12554260",
    "n":"2"
},
"script":"76a914641ad5051edd97029a003fe9efb29359fcee409d88ac"

But when query a transaction from https://blockchain.info, it seems differently: (http://ift.tt/2A3lebg)

"prev_out":
{
    "spent":true,
    "tx_index":8845778,
    "type":0,
    "addr":"1CfD77hupeUvFwBPxZ2fA8iyWmVwQY22oh",
    "value":10212000000,
    "n":1,
    "script":"76a9147fe34b97aeff4ab754770be5c8f12e2e95332fd488ac"
 }

Is there any document that clearly explains these data fields?

My current wonders:

1. What is the spent field?
2. There is no hash field at queried transaction, there must be i think?
3. What is type field?
4. Which fields are signed? The signature is generated by which fields hash?

http://ift.tt/2AW3oGW