SATA hard drives have a smaller connector cable than IDE. Most SATA drives also have a different power connector than IDE drives. IDE drives use large flat cables and a 4-pin power connector. SATA and SATA-II drives have a higher bandwidth--1. 5 Gbits/sec or 3 Gbits/sec.
IDE (Integrated Drive Electronics) is an older way of connecting storage devices to the system bus (usually on the motherboard of a PC). More recently developed SATA bus offers a more efficient (in both materials and speed) connection of storage devices to the computer. Most modern motherboards for desktop PCs support both IDE and SATA connections.
IDE is an older standard, now superceded by SATA. IDE has a maximum transfer rate of 133 Megabytes per second while the latest SATA 3.0 has 600 MB/s. Additionally, SATA offers enhancements such as native command queuing and hotplugging not available via the older IDE interface.
The difference between the two is the type of connection they have that connects them to the motherboard. One has a larger, older, connection cable with a bulky input. The newer version has a smaller, more streamlined cord with smaller, easier to use input. You should find out what kind of connection your pc has before replacing.
IDE and sata hard disks differs from the pin type only, ide hard disk contains 32 pins but sata hard disk contain only single pin through three or four connections. sata is very user friendly. sata hard disk pin are very small so use sata hard disks. both are same pin only differ.