# Topic 2 : Data and Data Representation

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Topic 2 : Data and Data Representation

## 1. Data, Information and Processing

### 1.1. Data Formats

1.1.1. Computers : process and store all data in binary format

1.1.2. Human Communication : includes language, images and sounds

1.1.3. Data formats : -specifications for converting data into computer-usable form -define the different ways human data may be represented, stored and processed by computer

### 1.2. Information processing cycle

1.2.1. collect data(input) ➡️ processing ➡️ produces information (output)

1.2.2. Processing – Data Coding

1.2.3. Processing - Data Storage and Compression

1.2.4. Processing – Data Integrity

### 1.3. Data, Information, Knowledge

1.3.1. Data ➡️ information ➡️ knowledge (applied for a purpose) (build&process)

## 2. Bits, Bytes, and Words

### 2.4. Number Bases

2.4.1. 1) Radix When referring to binary, octal, decimal, hexadecimal, a single lowercase letter appended to the end of each number to identify its type. E.g. hexadecimal 45 will be written as 45h octal 76 will be written as 76o or 76q binary 11010011 will be written as 11010011b

### 2.6. Octal System

2.6.1. New TopicAs known as base 8 numbering system There are only eight different digits available (0, 1, 2, 3, 4, 5, 6, 7)

### 2.7. Decimal System

2.7.1. Decimal is a base 10 numbering system We use a system based on decimal digits to represent numbers Each digit in the number is multiplied by 10 raised to a power corresponding to that digit position.

2.8.1. New TopicHexadecimal is a base 16 numbering system Used not only to represent integers Also used to represent sequence of binary digits

## 3. ASCII Codes, Unicode

### 3.1. The Alphanumeric Representation

3.1.1. The data entered as characters, number digits, and punctuation are known as alphanumeric data.  3 alphanumeric codes are in common use.  ASCII (American Standard Code for Information Interchange) Unicode  EBCDIC (Extended Binary Coded Decimal Interchange Code).

3.3.1. usage