The key difference between two important interface Sata& Pata

SATA vs PATA*
Compared to Parallel ATA, Serial ATA also has the benefit of cheaper cable costs and the ability to hot swap devices. To hot swap means that the devices can be replaced without turning off the entire system. With PATA devices, you'd need to shut off the computer before replacing the hard drive.

Note: While SATA drives support hot swapping, the device using it must as well, like the operating system.

SATA cables themselves are much smaller than the fat PATA ribbon cables. This means that they're easier to manage because they don't take up as much space and can be tied up more easily, if need be.

Also, the thinner design results in better airflow inside the computer case.

Like I said above, SATA transfer speeds are much higher than PATA. 133 MB/s is the fastest transfer speed possible with PATA devices, whereas SATA supports speeds from 187.5 MB/s to 1,969 MB/s (as of revision 3.2).

The maximum cable length of a PATA cable is just 18 inches (1.5 feet).