Digital Information Flashcards
Bit
The smallest unit of digital information. Each individual; one and zero in a binary sequence is a bit.
Byte
Eight bits together form a byte. The value of a single byte can range from 0 (eight 0s) to 255 (eight 1s).
Kilobyte (KB)
One kilobyte is equal to 1,000 bytes.
Megabyte (MB)
One megabyte is one million bytes of information. Therefore, 1 megabyte equals 1,000 kilobytes.
Gigabyte (GB)
One gigabyte is one billion bytes. Therefore, 1 gigabyte equals 1,000 megabytes.
Terabyte (TB)
One terabyte is equal to 1,000 gigabytes.
Digital data
A physical signal, such as text, numbers, graphics, or sound, is interpreted by converting it into binary numbers.
Encoding integers
Integers can have a positive or negative value. Computers encode 32 bit by using the first bit sign, on for negative and zero for positive. Then, the remaining 31 bits are used to encode the number itself, giving a range from about negative 2 billion to positive 2 billion.
Encoding text
Computers represent text by using 1s and 0s as stand-ins for physical signals, such as magnetic or electrical charge. The computer can encode text by assigning a unique binary code to each character.
Processing speed
In 64-bit processors, computers can receive or send eight bytes of data at once. Each time the processor writes data to memory or reads data from memory called a cycle. The bas unit of measure hertz (Hz). One hertz means one cycle per second. 1 kilohertz (KHz) = 1000 Hz 1 megahertz (MHz) = 1 million Hz (Often seen on an older PC bus interfaces.) 1 gigahertz (GHz) = 1 billion Hz (Often used with fiber optic networks. Newer computer CPUs run at gigahertz speeds.)
Storage space
Data storage usually refers to the number of bytes. Since bits and bytes are so small and cant store much information, we use the metric system to describe them in groups. 1 kilobyte = 1024 bytes 1 megabyte = 1024 kilobytes 1 gigabyte = 1024 megabytes 1 terabyte = 1024 gigabytes
Throughput
Throughput, or data transmission from one computer to another, usually refers to the number of individual bits that can b transmitted in one second. For example, a gigabit internet connection can send a billion ones and zeroes every second.
Throughput is also associated with PC bus speeds, or in other words, how quickly the system bus can move data from one computer component to the other. Some of the most common throughput terms are:
Kbps (kilobits per second) - 1 Kbps is equal to 1,000 bits per second. This type of throughput is sometimes found in slow network links or in public spaces such as a train.
Mbps (megabits per second) - 1 Mbps is equal to 1,000,000 bits per second. Often found in home networks and wireless networks. To get the bandwidth available to a memory controller in Mbps, multiply the MHz by 64 and then divide by 8.
Gbps (gigabits per second) - 1 Gbps is equal to 1,000,000,000 bits per second. Many modern networks and PC bus standards support Gbps.
Tbps (terabit per second) - 1 Tbps is equal to 1,000,000,000,000 bits per second and is often used when linking data centers, cities, and countries.
System Memory
A computer needs memory space available for processing. Processing