Fri 29 March 2024
Baydari.com

Data And Information

Data

A collection of raw facts and figures is called data. Data is collected from different sources. Data may consist of numbers of characters, symbols or pictures, etc.

Example

When students get admission in colleges or universities, they have to fill out an admission form. The form consists of raw facts about the students. These raw facts are the student’s name, father name, address, etc. The purpose of collecting this data is to maintain the records of the students during their study period in the college or university.

 

Information

The processed data is called information. Information is an organized and processed form of data. It is more meaningful than data and is used for making decisions. Data is used as input for processing and information is the output of this processing.

Example

In colleges and universities, the raw facts about students are stored on admission forms. If we want to find out a list of all students who live in Faisalabad, we will apply some processing on this data. This processing will give us the desired list. This list is a form of processed data and is called information.

 

Difference between Data and information

The difference between data and information is as follows:
 

Data

  1. Data is a set of raw facts.
  2. Data-is used as input in the computer.
  3. Data is not meaningful.
  4. Data volume is normally huge.
  5. Data is an asset of organizations and is not available to people for sale.
  6. Data is difficult or even impossible to reproduce. For example, if the Government loses the data of census if will be almost impossible to reproduce it.
  7. Data is used rarely.
  8. Data is an independent entity.
  9. Data is not used in decision-making.

 

Information

  1. Information is a processed form of data.
  2. Information is the output of the computer.
  3. Information is meaningful.
  4. Information volume is normally short.
  5. Information is normally available to people for sale.
  6. Information is easier to reproduce if lost. For example, if the list of illiterate citizens is lost, it can be reproduced easily from stored data.
  7. Information is used frequently.
  8. Information depends on data.
  9. Information is very important for decision-making.

 

Metadata

Metadata can be defined as data about data. It is used to describe the properties and characteristics of some other data. Metadata describes the size, format, and other characteristics of data. It also includes the rules and constraints of data.

Example

When you create a table, you specify the data type, size, format, and other constraints for entering data in different fields of the table. This is the metadata of the table. It describes the properties of the data to be stored in the table. Metadata is very important to ensure the integrity of the data.

 

Database

The database can be defined as an organized collection of related data. The word organized means that data is stored in such a way that the user can store, manipulate, and retrieve data easily. The word related means that a database is normally created to store my data about a particular topic. For example, if you create a database for students, it will contain the data about the students such as roll no, name, address, and other information about the students. Similarly, if the database is about the employees of an organization, it will contain the data of the employees such as employee ID; grade and salary, etc. All data in the database is arranged in tables.

 

Tables

The table is the fundamental object of the database structure. The basic purpose of a table is to store data. A table consists of rows and columns. A table is a very convenient way to store data. You can easily manipulate the data in a table.

 

Rows / Record

Rows are the horizontal part of the table. It is a collection of related fields. For example in the above, we have three rows. Each row contains a record of a different person.

 

Columns / Field

Columns are the vertical part of the table. For example, in the above table, all values under the” Name” field make a column.

 

Examples of Databases

Following are some important examples of databases:

 

1. Phone Directory

A phone directory is a simple example of a database. A phone directory stores the phone numbers of different persons. You can search for any phone number from the phone directory easily because all phone numbers are stored in an organized way.

 

2: Library

A library contains thousands of books. It is very difficult to handle the records of all these books without a database. A database system can be used to store the records of books, members of the library, issuance, and recovery of the books, etc. The user can use the database to search for the required books easily. This database can help a lot with doing research work.

 

3. Accounts

A database is used to control the accounts system of an organization. The accounts database keeps a record of all financial transactions. It can easily perform different calculations to find information about the business such as annual profit, trial balance, and ledger, etc.

 

4. College

A college has many students in different classes. A database may be used to keep the records of the students, fee transactions, examination information, and other data of the college. You can also store the attendance of the student in the database.

 

Hierarchy of Data

Data in computing: is classified in a hierarchy. Different terms are used to describe a dam of different levels in the hierarchy. A database contains files, a file contains records, the record contains fields and a field contains duration. The bit is the smallest' unit of data recognized by the computer. Eight bits make one byte. A byte is used to represent a character like '7', "1", ‘<', '$'.

 

Field

A field is a combination of one or more characters. It is the smallest unit of data that can be accessed by the user. A field is identified uniquely by field name. The data type of a field specifies the kind of data to be stored in the field. Common data types are as follows:

  1. Text: It is used to store alphabetic, numbers, and special characters.
  2. Memo: It is used to store lengthy text.
  3. Number: It is used to store numeric data.
  4. Currency: It is used to store numbers representing currency.
  5. Yes/No: It is used to store Boolean values True or False.
  6. Date: It is used to store month, day, year, and time.
  7. Hyperlink: It is used to store web address that links document or web pages.
  8. Object: It is used to store pictures, audio, video 0: a document created in other applications like MS Word or MS Excel.

A field size defines the maximum number of characters that can be stored in a field.

 

Record

A group of related fields is known as a record. For example, a student’s record includes a set of fields about the student such as Student ID, Name, Address, Email, and Phone, etc.

 

File

A file or data file is a collection of related records. Files are stored in the disk-like hard disk, CD-ROM, or DVD—ROM, etc. A Student file may contain the records of hundreds of students. Each student’s record consists of the same fields but each field contains different data.

The term file can also refer to the word processing, spreadsheet, or other executable application files. These are called program files. These files may or may not contain data.

A database is a group of related data files. For example, a student database may have data files like Student file, Fee file, Attendance file, and Exam file, etc. The data in the data files can be accessed by using a database management system.

 

Keys

Two types of important keys in databases are as follows:

 

Primary Key

A primary key is a field or group of fields that are used to identify each record uniquely in a file. It is also known as the key field. The data in the key field is unique for each record. For example, the Student ID field identifies each student uniquely because no two students can have the same ID.

 

Foreign Key

A foreign key is a field or combination of fields in a table that reference a primary key in another table. The key connects to another table when a relationship is being established between two tables. A table may contain many foreign keys.

 

Some important points of a primary key are as follows:

  1. It has the same name as the primary key from which it was referred.
  2. The field specifications of the primary key from which it was copied have to be the same for, the foreign key too.

Share