Originally Posted by holograph

processing used to secure and process transactions which is called mining. its based on controlled probability of finding encrypted solution for each new successful block (the block contains new transactions) which is added to blockchain (public transaction log system) and for each such found block miner is rewarded with X number of bitcoins, which is currently 50
as network grows it becomes more secure against attacks. Currently networks processing power is greater than 500 top supercomputers combined. Only way to attack the network is to have same amount or greater of processing power then block chain can be forked and you may be able to do some nasty things, if you would want to rewrite older older transactions in blockchain you will need to spend even greater amount of processing power. From this perspective network isn't 100% secure but with such processing power attacker will be more profitable at mining then corrupting the network. Sorry I side-tracked but there is lots of stuff behind how this technology works with very elegant math solution to keep it decentralized and secure.

Bitcoin worth is really in ability to make fast and cost effective transactions in a secure decentralized way. This is first tech that can be greatly utilized for micro-payments as well.

Too much into to be able to put in few paragraphs hopefully I didn't make it more confusing.