My first modern computer was an Intel 286-12 with 1MB of memory and a 20MB HDD back in the day over 20 years ago. Today the typical modern computer is a Core i7 870 which is clocked at 3.2GHz with 4GB of DDR3 memory and a 2 Terabyte HDD. As you can see, the modern computer has evolved significantly over the last 20 years.
The modern HDD is a different beast than the IDE HDD of a few years ago. The replacement for the IDE HDD was the Serial ATA interface which offered similar performance to the PATA standard. Early SATA solutions required a Bridge chip which lacked support for features like NCQ. SSD drives are available providing faster performance but lack in the storage category as large capacity drives are confined to the traditional HDD. Today marks the rollout of the first SATA 6Gigabit/second drives which is considered the third generation of SATA and the first 6 Gb/second drive I have on the review bench is the Seagate 2TB Barracuda XT drive.