This is an annotated version of Blockchain.info's Websocket API with explanations of message contents.
Bitcoin transactions (especially if large) may have multiple inputs and outputs in a single transaction. http://chimera.labs.oreilly.com/books/1234000001802/ch02.html explains this very concisely.
The JSON object below is the actual message received from the Blockchain.info Websockets API for the transaction 0857b9de1884eec314ecf67c040a2657b8e083e1f95e31d0b5ba3d328841fc7f. You can see the Blockchain.info transaction page for this transaction here.
Transaction Page: https://blockchain.info/tx/0857b9de1884eec314ecf67c040a2657b8e083e1f95e31d0b5ba3d328841fc7f
{
"op" : "utx",
"x" : {
"lock_time" : 0,
"ver" : 1,
"size" : 520,
"inputs" : [ { // Array consisting of multiple "inputs", which are debits against a bitcoin account
"sequence" : 4294967295,
"prev_out" : { // Indicates source funds is from a previous 'out' transaction
"spent" : true,
"tx_index" : 301966400,
"type" : 0,
"addr" : "1Y1gGHcFHajh9oY6WzeS4qxhjZoptfHts",
"value" : 55000000,
"n" : 6,
"script" : "76a91405dd75bcc1d3893e24031a81cb882d8ff586ce0888ac"
},
"script" : "483045022100d0fdb06b26cbe1dfccb32b44e2c2e81a5a51f98df4b6b5f7bf164597026a5f4b02201a7aaf6bf8bbcdf2c4d4b5df48ad5ff4f457fc0dd5f112bc0eceb643198d8c9e012103684b3d6c7709e242f91ff2e14dfa865b7580076416b8e1a9a487de7519136995"
}, {
"sequence" : 4294967295,
"prev_out" : {
"spent" : true,
"tx_index" : 300795215,
"type" : 0,
"addr" : "15bvuNL41gjkRXcp33r695YoZZwkrikDGG",
"value" : 55310,
"n" : 0,
"script" : "76a914327ba446b94cc0ca296658fc633e99dafc0e3ad788ac"
},
"script" : "4730440220074ff9df86e2dbd4f6c50de56638fe6b40d58b565e725907487144ac78dffbb502206b9af46cd6314fb85679a06cf1f71700e69adb67996fd13947c4ab8f1a7a2f6701210301ee3ca3e53caf1ef0cd63924e96269be821820cff02262799d9179d44e41cdb"
}, {
"sequence" : 4294967295,
"prev_out" : {
"spent" : true,
"tx_index" : 301657981,
"type" : 0,
"addr" : "1362EzLHB7tsvWJ1KYzXzmPSwU7JpFnib7",
"value" : 109709,
"n" : 1,
"script" : "76a91416e35e11ff0e6fe8c8f5334c0f40cc05908a651a88ac"
},
"script" : "47304402207e8654bfa5e88effeee009f4bc334297b7b03f64e5218a514483d35fb43b97bf022078f714aa2035566def5dd80a4b389d014bc6a8f61e63e35202600e4785b0ad81012102b6a2be4beeadf05eaba12b2f50fbb31a436f7d9a1b402d91f81b079c5c6c6fa5"
} ],
"time" : 1510912841,
"tx_index" : 302021857,
"vin_sz" : 3, // Number of "inputs"
"hash" : "fa8ef2dc2241b89e5e7f2189fc522568620e4a3aae08b39cf38771a1006f4055", // This is the transaction hash
"vout_sz" : 2, // Number of "outputs"
"relayed_by" : "0.0.0.0",
"out" : [ { // Array consisting of multiple "outputs", which are credits to a bitcoin account
"spent" : false,
"tx_index" : 302021857,
"type" : 0,
"addr" : "154dXFjRPukDFqZpRU7GfBDMCrkmbZXNsH", // This is the main transaction amount
"value" : 55000000, // Value in satoshis
"n" : 0,
"script" : "76a9142c903cdc224e8b75b3f573014ec8c1f743854c1f88ac"
}, {
"spent" : false,
"tx_index" : 302021857,
"type" : 0,
"addr" : "1NT1YgyA8RfrhVNUBJx6kRkwF899z1c5NA", // This is the fractional share
"value" : 65269,
"n" : 1,
"script" : "76a914eb45e99cb640e616f0de08e6a1fc4bba063a115a88ac"
} ]
}
}