Miners gather the transactions on the network into expansive groups called blocks. These blocks are hung together into one constant, authoritative record called the block chain, which doesn't allow any clashing transactions. This is fundamental in light of the fact that without it individuals would have the capacity to sign the same Bitcoins over to two unique beneficiaries, such as composing checks for more money than you have in your account. The block chain tells you without a doubt precisely which transactions tally and can be trusted.
The way bitcoin
ensures there is just a single block chain is by making blocks truly hard to deliver. So rather than simply having the capacity to make blocks freely, excavators need to process a cryptographic hash of the block that meets certain criteria. Bitcoiners allude to this procedure as "hashing". The best way to locate a cryptographic hash that is "adequate to count" is to take a stab at processing an entire cluster of them until the point when you luck out and discover one that works. This is "lottery" since diggers who effectively make a block are compensated some Bitcoins as per a preset timetable. The trouble of the criteria for the hash is constantly balanced in view of how every now and again blocks are showing up, so more competition levels with more work expected to discover a block.