Data Connectors:

HDD connectors: A typical HDD connector has 40 pins, on the hard disk, there are 40 holes, this combination works perfectly.

ATA connectors: They actually make use of ATA transmission standards, the cable has 80 pins compared to the 40 pins to normal HDD connectors. The information retrieve from a hole is split up into two and then transmitted, thus data transfer is much faster.

CD-ROM connectors: It has the same shape as the HDD connector but data transmission is not as fast because of limited access speed of CD-ROM drives.

Floppy Connectors: They are physically smaller than HDD and CD-ROM connectors because the rate of data transmission is much slower compared to the two.