Basically a hash is a mathematical equation which is created in the hopes of solving within the Bitcoin and Litecoin mining process. A Bitcoin and Litecoin block is made when the mathematical equation is solved. A specialized mining rig is designed to process massive amounts of mathematical equations per second.
One Gigahash processes one BILLION hashes per second, pretty amazing computational power!
And one Gigahash equals one thousand Megahash per Second.
The more hashes that are processed per second, the faster your rig will create Bitcoins and Litecoins. Now the Bitcoin and Litecoin process has been designed that the more coins which are mined, the more difficult the mathematical equations will be to achieve. So even though your mining machine will create the same amount of hashes per second, eventually you will mine less and less coin.
Check out our post http://coinminers.net/fastest-easiest-ways-buy-bitcoin-online/ on how to obtain bitcoins. Very useful information
UPDATE: You can now purchase cloud hashing by the gigahash and fraction of a gigahash at:
Here you can buy sell and trade Cloud Hashing contracts. Please check it out, I highly recommend it.
Here is the place to go if you would like to trade bitcoins for other cryptocurrency: