A bit or binary digit is the minimum unit of information that is stored in a computer system. It can have only two states -on or off which are commonly used as zeros and ones. Moreover, the combination of 0’s and 1’s decides which information has to be entered into and processed by the computer.
Definition of Binary Digit
In the computer term, bit or binary digit is the smallest unit of information which is used to store information and has a value of true/false or on/off. An individual bit has a value of either 0 or 1 which is usually used to store the data and execute instructions in groups of bytes. A byte in computer is made up of eight bits.
In binary, every digit represents a power of two. Each decimal code is represented in binary as a set of four binary digits or digits. However, it is said that the computer’s memory units are both the bit and the byte. The pace of data transfer is measured with the help of bits. On the other hand, memory is measured in bytes. Most of the systems use either 32-bit lengths to form a word or 16-bit lengths to form a half-word.
Below are some units of information which contains multiple bits
- Byte – 8 bits
- Kilobit – 1,000 bits
- Megabit – 1 million bits
- Gigabit – 1 billion bits
Why Binary Digit (BIT) is Required?
Unlike humans, computers do not understand words or numbers. Each and every number in the computer system is an electrical signal. In the early days of computing, electrical signals were very hard to measure and control accurately. So a classification was done to make it easy, and that was to to observe just On and Off state. On state was represented by negative charge and off state was represented by positive charge.
Modern software lets the end user to ignore this, however, at the lowest levels of the system, everything is represented by a binary electrical signal in two states which is on and off. Binary is a base 2 system which means there are only two digits – 0 and 1 that correspond to on and off states for the computer to understand. The computer has to encode the data in binary if it looks like a complicated data. Latest computers store bits with the help of electromechanical transistors to execute calculations with binary digits which can map electrical signals to either switch off or on mode.
How Data is Stored?
Data is stored in memory devices which comprises memory cells. They are tiny electronic components capable of holding a bit of information. These cells can exist in different states, typically represented as 0 (off) or 1 (on), depending on the technology used.
A data is transformed into binary code before storage. For instance, text characters are assigned unique binary representations using character encoding schemes like ASCII or Unicode. Images, audio, and video files are also encoded into binary format. Also, Memory devices use a system of addresses to locate and retrieve specific data. Each memory cell is assigned a unique address, making it possible to read and write data to precise locations.
To save new data or modify existing information, the memory controller writes the updated binary code to the appropriate memory cells. This process ensures that the device can store and update data as required.
Binary Code of Data
For Upper case and Lower case, there is a binary code which is as shown below –
A – 01000001 a – 01100001
B – 01000010 b – 01100010
C – 01000011 c – 01100011
It takes four eight-bits bytes to form a 32-bit word. Storing a single character requires eight bits. One byte or eight bits can produce 256 distinctive combinations of numbers, letters, symbols and characters.
What is Nibble?
A nibble is a term used to refer to a group of four binary digits (bits) or half a byte. It represents a smaller unit of data than a byte, which consists of eight bits. Nibbles are often used in computing for various purposes, including data storage, data transmission, and low-level data manipulation.
In a nibble, each of the four bits can represent one of 16 possible values, ranging from 0000 (binary 0) to 1111 (binary 15). Nibbles are commonly used in hexadecimal (base-16) representation because each nibble corresponds to a single hexadecimal digit. For example:
- Binary 0000 corresponds to hexadecimal 0.
- Binary 0001 corresponds to hexadecimal 1.
- Binary 1010 corresponds to hexadecimal A.
- Binary 1111 corresponds to hexadecimal F.
Nibbles are particularly useful in systems where data needs to be converted between binary and hexadecimal representations or when dealing with data at a lower level, such as in assembly language programming or hardware interfacing. They provide a more compact way to represent and manipulate data compared to dealing with individual bits.
Bits in Computer Processor
The processors of early computers were 16-bits processors which had the capacity to work with 16-bit binary numbers (decimal number up to 65, 535). Anything above, the computer would need to break up the numbers in to small pieces. At later stages, the processors were 32-bit, which had the capacity to work with 32-bit binary numbers. However, in today’s generation, computers have 64-bit which had the capacity of 64-bit binary numbers.
Also, using bits, the computer’s processing power may be measured to know how many bits can be processed by a computer at a time. The number of bits used in graphics, every dot reflects the color, quality and clarity of the picture. The number of bits per second is communicated over a week.
History of Bits
In the year 1732, Basil Bouchan and Jean-Baptiste devised the bit using punch cards. Then, these bits were used to encode the data. Sir Joseph Mary Jaccard then created in the year 1804. In the year 1844, the use of encoding text by bits were performed in Morse code and later in the year 1870, it was even used in digital communications machines.
Later, in 1948, the “bit” word was used by Claude E. Shannon for the time in his seminal paper called “A Mathematical Theory of Communication”. However, Claude credited its basic to John W.Tukey who was the writer of the Bell Labs . He contracted the binary information digit to a bit in bell labs.
Bits in colors
Bits play an important role in colors as they help to calculate color depth by 2 to the power of the bit color.
Working of Bits
In a byte, each bit is allocated with a specific value which is known as the place value. They are used to decide the meaning of the byte depending on the individual bits. To simplify, the value of the bytes shows what character is related with that byte.
A place value is allocated to each bit in a right-to-left pattern, beginning with 1 and increasing the value of doubling it for each bit as shown below –
| Bit Position (right to left) | Place Value |
| Bit 1 | 1 |
| Bit 2 | 2 |
| Bit 3 | 4 |
| Bit 4 | 8 |
| Bit 5 | 16 |
| Bit 6 | 32 |
| Bit 7 | 64 |
| Bit 8 | 126 |
The place values that used with bit values to arrive at the byte’s overall meaning. Hence, to calculate this value, the place values associated with each 1 bit are added together. This total corresponds to a character in the applicable character set. To note, a single byte can support up to 256 unique characters starting with 00000 byte and 111111 byte. Different combinations of bit patterns offers a range of 0 to 255, that means each byte can support up to 256 unique bit patterns.
What can Bit do?
Bit is just a single number, 0’s and 1’s. These bits can be combined to create large units like bytes, megabytes, etc. to measure the files. The larger a file, the more bits it has. For example – high resolution video is made up of millions and billions of ones and zeros. Binary is easy for the computers to process and they also occupy less space.
Read Also: Decimal & Binary Computer Number System – Conversion of Decimal to Binary & Binary to Decimal
