ilichbustamante :
what is the difference between the two and which is better ?
The technology. SSD's use NAND Flash to store data while hard drives use magnetic platters.
The end results, SSD's are about 5 times faster overall (instant access and great random I/O), more durable, consume less power, and less prone to failure (lack of mechanical parts), and silent. The downside: Price and capacity. SSD's don't store a lot, the cost quite a bit, especially for the larger capacities. While prices of SSD's have plummited, they are still much more expensive than hard drives on a price per GB scale.
Personally, SSD's are better, no comparison. The only time an SSD wouldn't be better is if you are archiving media where the extra performance isn't...