HD is the term used to differentiate the systems that generate, transmit or support HD content (High Definition) with those of standard definition or low definition (SD).

HD resolutions are usually at least 1280 x 720 pixels by taking the ratio "width x height". Being the height, 720 pixels, which make high resolution.

Serial ATA or SATA (acronym for Serial Advanced Technology Attachment) is a data transfer interface between the motherboard and some storage devices such as hard disk, regrabadores readers and CD/DVD/BR, SSDs or other high performance devices are still being developed. SATA I Frequency: 1500 MHz Bits: 1. Bits 8 Real Speed: 150 MB/s. SATA II. Frequency: 3000 MHz Bits: 1 bits 8 Real Speed: 300 MB/s. SATA III Frequency: 6000 MHz Bits: 1. Bits 8 Real Speed: 600 MB/s eSATA. SATA type connector for connection of external peripherals.

Serial Attached SCSI or SAS, is an interface for serial data transfer, the successor to SCSI (Small Computer System Interface) parallel, but still uses SCSI commands for interacting with SAS devices. It increases speed and allows connection and disconnection quickly. The first version appeared in late 2003: SAS 300, getting a bandwidth of 3 Gbit/s, which increased the speed slightlyits predecessor, the Ultra SCSI 320 MB/s (2.560 Gbit/s). The next evolution, SAS 600, achieves a speed of up to 6 Gbit/s, while expected to reach a speed of about 12 Gbit/s circa 2010.

Secure Digital (SD) is a memory card format for portable devices such as digital cameras, mobile phones, laptops and even game consoles (both desktop and laptop), among many others.

SDHC Speed Class 2 Class 2 2 MB/s
SDHC Speed Class 4 Class 4 4 MB/s
SDHC Speed Class 6 Class 6 6 MB/s
SDHC Speed Class 10 Class 10 10 MB/s
UHS Class 1 UHS Class 1 10 MB/s
UHS Class 3 UHS Class 3 30 MB/s

The SFF connectors are distinguished by their smaller size, they are ideal for saving space. The SFF connectors also increase port density cards, switches etc ..