Bit and byte

I have encountered some vague concepts in my work and need to remember them.
Bit indicates "bit" or "bit", which is the basis of computer computation;
Byte indicates "Byte", which is the basic unit for calculating the computer file size;

The transmission rate of the USB2.0 standard interface. Many people misunderstand "480 Mbps" as Mbit/s. In fact, this is wrong. In fact, "480 Mbps" should be "480 megabits/second" or "Mbps/second", which is equal to "60 Mbps/second ", let's see the gap.
This should start with bit and byte: Bit and byte are both measured units, bit = "bit" or "bit ".
Byte = byte, that is, 1 byte = 8 bits. The conversion between the two is.
Mbps = mega bits per second (second/second) is the rate unit, so the correct statement is that the transmission speed of USB2.0 is 480 second/second, that is, 480 Mbps.
MB = mega bytes (megabytes, megabytes) is the unit of measurement, 1 Mb/s (megabytes/second) = 8 Mbps (Bytes/second ).
The hard disk capacity is 40 GB, 80 GB, and 100 Gb. Here, B Refers to byte, which is "byte ".

1 kb = 1024 bytes = 2 ^ 10 bytes1 MB = 1024 kb = 2 ^ 20 bytes1 GB = 1024 MB = 2 ^ 30 bytes

For example, in the past, the so-called 56kb modem was converted to 56kbps divided by 8, that is, 7 Kbyte, so the actual speed of downloading files from the Internet is 7 Kbyte per second.

That is to say, B, which is related to the transmission speed, generally refers to bit.

Capacity-related B generally refers to byte.

Finally, the transmission rate of 480 Mbps = 60 Mbit/s is only a theoretical value, and it is also restricted by the system environment (CPU, hard disk, and memory ), the actual speed of reading and writing data to the hard disk is about 11 ~ 16 Mb/s. However, this is nearly 10 times faster than the 12 Mbps (1.5 m/s) of USB1.1.

 

[PS]: Int = 4 byte = 32 bits in Java