[The difference between literacy]bit and byte

Many people have asked this recently, it is necessary to sweep the literacy.
Bit means "bit" or "bit", which is the basis of computer operation;
byte means "byte", which is the basic computing unit of computer file size;

Speaking of USB2.0 standard interface transfer rate. Many people have misunderstood "480mbps" as 480 megabits per second. In fact, this is wrong, in fact "480mbps" should be "480 megabits per second" or "480 megabits per second", it equals "60 megabytes per second", we see the gap.

This starts with bit and byte: The bit and byte are translated as "bits", which are data measurement units, bit= "bit" or "bit". The byte= byte is 1byte=8bits, and the two conversions are 1:8 relationships.
Mbps=mega bits per second (megabits per second) is the rate unit, so the correct argument should be that the USB2.0 transmission speed is 480 megabits per second, or 480mbps.
Mb=mega bytes (megabits, megabytes) is the unit of measure, 1mb/s (MBytes/sec) =8mbps (megabits per second).

What we call the HDD capacity is 40GB, 80GB, 100GB, here the B refers to the byte is the "byte".
1 KB = 1024x768 bytes =2^10 bytes
1 MB = 1024x768 KB = 2^20 bytes
1 GB = 1024x768 = 2^30 bytes

For example, the so-called 56kb Modem converted to 56kbps divided by 8 is 7kbyte, so the real download of files from the Internet is the speed of the hard disk is 7kbyte per second.
That is, B, which is related to transmission speed, generally refers to bit.
A capacity-related B generally refers to a byte.

Last but not least: the transfer rate of the USB2.0 480mbps=60mb/s is only a theoretical value, it is also subject to the system environment (CPU, hard disk and memory, etc.), the actual read, write to the disk speed of about 11~16mb/s. But it's also nearly 10 times times faster than usb1.1 's 12mbps (1.5m/s).

The transmission speed of 56kbps=7kbyte/s is also the theoretical value.