Block Header
Update shuda Aug 18, 2026 Block header, blockchain mein
block ka ek khulasay ka section hai jis mein is ki mukammal transaction list ki bajaye block ka bunyadi shanakhati data shamil hota hai.
Header mein woh
metadata mojood hota hai jo block ki wazahat karta hai: Is ko kab banaya gaya tha, yeh pichlay block se kaise jura hai, aur ek wahid hash jo is mein shamil tamam transactions zahir karta hai. Asal mein, block header mein transactions ki asal fehrist ke ilawa block ke baray mein sab maloomat shamil hoti hain.
Bitcoin mein, block header chay fields par mushtamil ek teh shuda 80-byte ka structure hota hai:
Version: is baat ki taraf ishara karta hai keh block kin consensus ke qawaed par amal karta hai, aur usay protocol upgrades ke liye support zahir karne ke liye istemal kiya ja sakta hai.
Previous block hash: Pichlay block ke header ka
hash hota hai, jo blocks ko aapas mein ek chain ki shakal mein jorta hai.
Merkle root: ek wahid hash jo keh block mein mojood tamam transactions se hasil kiya jata hai, jo
Merkle root ke structure se banaya gaya hai, aur isi liye transactions mein honay wali koi tabdeeli is value ko badal deti hai.
Timestamp: block ke banaye jane ka andazan waqt record karta hai, jise Unix timestamp ki soorat mein zahir kiya jata hai.
Difficulty target (nBits): yeh us hadd ko encode karta hai jis se header hash ki value lazmi tor par kam honi chahiye. Network difficulty barah-e-raast store kiya jane ke bajaye isi target se hasil ki jati hai.
Nonce: ek counter jis ko miners mozoon hash talash karte waqt
nonce field ke zariye musalsal tabdeel karte hain.
Block header woh hota hai hai jis ko miners block ko mustanad banane ke liye hash karte hain. Chunkeh header sirf 80 bytes ka hota hai, is liye yeh block mein mojood har transaction ko hash karne se kahin ziada moassar hai, jabkeh transactions ki tadaad hazaron mein ho sakti hai. Jab kisi block ko
mine kiya jata hai, to header ko dohray SHA-256 hash se guzara jata hai, aur nateeja block ka shanakht kaar ban jata hai.
In ka chota size block headers ko light clients ke liye mufeed banata hai. Mukammal
Bitcoin blockchain ko mehfooz karne ke liye kafi ziada storage ki zarurat ho sakti hai, lekin jo device sirf block headers mehfooz karti hai woh is storage ka bohat chota sa hissa istemal karti hai. Chunkeh har header Merkle root ke zariye apni transactions record karta hai, is liye ek light client puri chain downlaod kiye baghair, baad mein ye dekh sakta hai keh kia makhsoos transaction block mein shamil thi ya nahi. Yeh tareeqa abhi tak data ke liye third party par inhisar karta hai, lekin yeh mehdood wasayil ki hamil devices ko kuch hadd tak toseeq ki ijazat deta hai.