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What is a database?

As the role of technology becomes manifold in every sector, it generates huge amounts of information that can yield valuable insights about the domain. This has led to a boom in data generation in the last two decades and everyone is talking about a database. Let's explore what a database is.

What is data?

Data are units of information, often numerical, collected through observation. In a more technical sense, data is a set of values for qualitative or quantitative variables about one or more people, while data (singular data) is a single value for a single variable.

Although the terms “data” and “information” are often used interchangeably, these terms have distinct meanings. Information is data collected to draw meaningful conclusions according to its contextual requirements. Information is organized, processed and presented in a specific sense which improves the reliability of the acquired data.

what is the database?

A database is an organized collection of data organized to make it easy to access, manage, and update. In simple words, you can say, a database is a place where data is stored. You can imagine the database as a library. The library has a huge collection of books of various types, so the library is a database and the books are the data.

Hierarchy of data in a database

Data stored in computer systems form a hierarchy that extends from a single bit to a database, which is the main record-keeping entity in a company. Each rung up this hierarchy is organized from the components below it.

The data is logically organized into:

  • Bit (characters)
  • fields
  • Records
  • Files
  • Databases
  • bit (character)

A bit is the smallest unit of data representation (the bit value maybe 0 or 1). Eight bits make up a byte that can represent a letter or a special symbol in the character code.


A field consists of a set of characters. A data field represents an attribute (property or quality) of an entity (object, person, place, or event).

A group of one or more characters is called a field. It is the smallest unit of data accessible to a user. The name of each field in the record is unique. A field data type refers to the type of data that can be stored in the field. Each field contains one specific piece of information. The field size determines the maximum number of characters that can be stored in the field. For example, the Employee Number, Employee Name, Grade, and Designation fields are the fields.


A record represents a set of attributes that describe a real entity. A record consists of fields, and each field describes an attribute of the entity.

The collection of related fields as a single unit is called a record. For example, an employee record includes a set of fields containing employee number, employee name, grade, and designation.


A file is a collection of related records. Files are often categorized by the application for which they are primarily used. A primary key in a file located in the field (or fields) whose value identifies a record among others in the data file.

A group of related records treated as a single unit is called a file. A file is also known as a data set. The files are stored on a disk such as a hard disk, CD, etc. An employee file may contain records of all employees in the organization. Each employee's record consists of the same fields but each field contains different data.

Uses of database system

The database system serves the following functions.

They store data and provide facilities (tools) to search for specific records in a particular set of data.

They store private information used to manage data. This information is called metadata and is not visible to all users who look at the data.

They can solve cases where multiple users want to access (and possibly change) the same data entities.

They manage access rights (who is allowed to see the data, and who can change it).

When many users ask queries to the database, they should be answered faster. This way, the last person to ask a question can get an answer in a reasonable time.

Some attributes are more important than others and can be used to find other data. This is called indexing. The index contains all the important data and can be used to find other data.

They ensure that data always has context. There are a lot of different rules that can be added to tell the database system if the data makes sense. One rule might say that November has 30 days. This means that if someone wants to enter November 31st as the date, that change will be rejected.

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