> What does X mean in the term 16X on the CD/DVD ROM ?
"x" = speed; i.e. 48 speed CD-ROM. Refers to how quickly the drive will read the disk. same deal for writing to disks. Speed increased incrementally from single speed (1X) CD-ROM. On a burner, it'll say for example 4X4X8, which would be 4 speed write, 4 speed rewrite, 8 speed read (I may have write & rewrite backwards). Those are always max speeds, doesn't necessarily mean the rated speed is constant. 

> What are PCI Slots?

A PCI slot is used to add extension cards to a machine. The PCI world is somewhat of a mess right now. There are at least TEN different types of PCI sockets in use!

* Original PCI.
* Wide PCI.
* Fast/wide PCI.
* Fast/wide 3.3-volt PCI.
* PCI-X.
* Narrow PCI-X.
* PCI-Express x1.
* PCI-Express x4.
* PCI-Express x8.
* PCI-Express x16.

Today, mainly the x16 is used for Graphic cards, and PIC is used to connect network cards.

> What are the types of Printers?
Dot matrix printers, Characters printer, Ink jet printers, Laser printers . 

> What is the difference between DDR1, DDR2 and DDR3 memories ?
# DDR stands for Double Data Rate. Like SDRAM, it operates at the rate of the computer's clock cycle. However, unlike SDRAM, it can transfer data twice per clock cycle. It does this by using the rising and falling edges of the clock signal, also known as "double pumping" and employing a prefetch buffer capable of accessing two datawords at a time. This means that it can store and move a value in the same amount of time it takes SDRAM to do one or the other, effectively doubling the memory's speed.

# DDR2 also utilizes the same double pumping technique as DDR. It achieves performance gains by using a prefetch buffer that retrieves four datawords per memory access. This allows it to transfer data four times per clock cycle (compared to twice in the case of DDR). According to Bit-Tech.com, its improved efficiency allows it to consume less power than DDR.

# Like all other forms of DDR, DDR3 transfers data twice per clock cycle. However, its prefetch buffer can access eight datawords at a time, according to Benchmark Reviews. Thus, it can transfer data eight times per clock cycle, giving it a maximum data transfer rate twice that of DDR2 while using less power.

> What are the types of Hard-disk drives ?
Disk drive technologies have advanced quickly over recent years, making terabytes of storage available at reasonable cost. When researching the type of hard disk storage system appropriate for your needs, keep in mind the format and data rate of the video you’re capturing. Depending on whether you work as an independent video editor or collaborate with others, the amount of storage you require and the bit rate of data transfer will be important factors to match up with your storage needs. Outlining all of the hard disk storage technologies is beyond the scope of this documentation, but four common choices include:

* ATA
* FireWire
* SCSI
* RAID and Fibre Channel