Analog vs Digital Data

• Information Technology Fundamentals is about Analog and Digital data

Analog and digital data

• Analog devices recognize data as a continuous measurement of a physical property.
• Analog outputs are displayed on a meter or graph.
• Examples of analog devices are analog clocks, car speedometers, and thermometers.
• Digital devices work with discrete numbers.
• Digital devices describe everything in two states "on/off"
• Digital devices involve short bits of data.
• Real-world objects can display data, and gather inputs by either analog or digital means.
• Analog representation uses a continuous range of values, usually infinite, such as sound, height, and weight.
• Digital representation uses discrete values, usually finite, such as the number of people, age, integers, and price.
• Digital data stored in the computer are in the form of binary bits.
• Discrete data have a minimum unit of quantity while continuous data does not have one.
• Something continuous (analog) can usually be measured, while something discrete (digital), can usually be counted.
• Original forms of analog data signals are hard to process, manipulate, change, modify, or operate.
• Analog needs to be converted into another easy-to-be-processed form for effective and efficient processing.
• Transforming different kinds of data into numbers can be considered an approximation procedure.
• Approximation is sufficient for practical applications therefore the infinite and infinitesimal exist only in theory.
• The precision needed to measure the dimensions of an object depends on the level required (e.g., km, m, cm, mm, μm, or nm)
• Finding the exact dimensions of an object is impossible and unnecessary.
• Arithmetic, relational, and logical operations are available in digital systems which can lead to compression and encryption.
• Digital systems are more resistant to noise than analog systems but are still susceptible to noise.
• Excessive noise can generate incorrect results and errors.
• Digital systems can incorporate control systems capable of detecting and correcting errors.
• Analog technologies degrade under environmental conditions and due to age; digital technology is less prone to quality decline
• Transmission of digital data is easier since signals are generated with only one of two values.
• Digital Technology protects data via security techniques such as encryption.
• Data that is intercepted over unsecured telephone and Internet networks cannot be deciphered.
• Discrete data 'things' such as, records, events and messages are more easily processed digitally.
• ''Digitizing" is capturing analog data by converting analog data/ signal into digital representation which allows the processing of analog data via capture and representation as a series of numbers.
• Sampling is the most common method to convert analog data/signals into digital representations.
• A codec is a device or computer program to convert analog signals to digital signals, and vice versa.

Data types

• Data is generally divided into numbers(numeric) and non-numbers(non-numeric).
• Data representation for numeric data should consider the number system, the bits, the binary point, how large the numbers can be and how the numbers are represented.
• Representing non-numeric data is called encoding.
• A unique "ID" is assigned to a piece of data.

Binary System

• In computers, numeric data needs to be represented by a numbering system that best suits computers,
• Numbering systems include decimal (base-10), sexagesimal (base-60), and binary (base-2).
• Using binary is easier in the computer.
• Binary system digits, or bits are either are 0 and 1
• Eight bits grouped together is called a byte.
• The electronic circuits can easily represent states via binary.
• The binary system uses states such as 'on and off', 'high and low', or 'has charge and has no charge'

Conversion between base-10 and base-2

• To Convert base-10 to base-2 repeatedly divide by 2 and arrange the remainders from bottom to top.
• To Convert base-2 to base-10 raise each digit by ascending powers of 2 from right to left.

Representing the bits for numbers

• Select a numbering system to determine how many bits should be used to represent N numbers.
• Number of bits used affects number of different numbers in computer.
• Eight bits represents 2^8 = 256 different numbers.
• Sixteen bits represents 2^16 = 65536 different numbers.

Encoding

• Encoding represents non-numeric data using only 0s and 1s
• If 0 represents 'a' and 1 represents 'b', the computer "knows" when it runs into 0 or 1.
• 2 bits yield 4 different codes such as: 00, 01, 10, and 11 which can represent 4 different letters.
• The English letter 'A' can be represented through a code such as (ID, 01000001), and then record its shape through a binary matrix.
• When displaying the shape of ‘A’, the code finds the shape and the shape is also represented through bits.

Encoding characters

• Single-byte encoding and multibyte encoding are types of encoding for plaintext.
• Single-byte encoding uses 8 bits to represent total 2^8 = 256 different codes, sufficient for most western languages
• ASCII (American Standard Code for Information Interchange) is the the most common single-byte encoding for English
• EBCDIC (Extended Binary Coded Decimal Interchange Code) is another example of single-byte encoding.
• The encoding handles English language alphabet letters (both little and capital letters), numbers (0-9), punctuation marks, special keys on keyboard (SPACE), and some special characters.
• Multibyte encoding methods are needed to represent more complicated alphabet systems.
• The GB encoding encodes simplified Chinese characters or Big5 encoding encodes for traditional Chinese characters, both encoding using two bytes.
• Another encoding method is the Unicode that codes representation for almost all scripts in current use today, which can also use more than 2 bytes.

Encoding Colors

• Color depth refers to the number of bits used to represent the colors, with more bits representing more colors.
• 1 bit for 2 colors.
• 2 bit for 4 colors.
• 3 bit for 8 colors.
• 4 bit for 16 colors
• 5 bit for 32 colors
• 6 bit for 64 colors.
• 7 bit for 128 colors.
• 8 bit for 256 colors.
• 16 bit for 65536 colors.
• 24 bit for 16,777,216 colors.
• The number of colors increases with higher color depth as seen via the display types:.
• HD displays 1920 x 1080 and uses 8-bit with 16.7 million (256^3) colors.
• 4K displays 3840 x 2160 and uses 10-bit with over 1 billion (1024^3) colors
• 8K displays 7680 x 4320 and uses 10-bit with over 1 billion (1024^3) colors

Explanation of the fundamental differences between analog and digital data. Includes their representation, examples of analog and digital devices, and real-world applications. Describes how digital data is stored in computers using binary bits.