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Key terms in Database and Introduction to database


General Terms:

DataBase:

A container in which we can store data in an organized manner.

SQL:

SQL is a language which we use to talk to Database.

DBMS:

A software which can understand SQL or Database language and can manage database.

Server:

A physical device where data is stored. Although it is not the only task of the server, but it is one of its tasks among running actual website code, accept http requests etc.

Analogy:

So, database is just collection of files in an organized manner i.e the data organized in any format (tables, key values etc) is named as database. It is similar to the concept, if we organize our data in some format which we decide to follow, then we would call it our database. At the end of the day, it is just data that is being stored on some storage device and in an organized manner. That's what happens in case of server, data is stored in an organized manner in specialized storage device of the server.

Schemas:

a category or logical container, it is like a virtual format which we follow. We can use it to group up related objects.

Tables: 

Collection of rows and columns i.e. fields and records.

Field/Attribute:

One column is a field or attribute.

Record:

One row is a record. 

Primary Key:

A single attribute or collection of attributes which are unique is called primary key. Primary key can have more than one attribute.

Types of SQL Commands:

DDL(Data Definition Language):

This involves:

  • CREATE (create tables with fields)
  • ALTER (to change something that already exists, i.e change the attribute names or types or anything related to that)
  • DROP (Delete a column i guess)
DML(Data Manipulation Language):
  • INSERT (put data into the created table)
  • UPDATE (update or alter the added data in the table)
  • DELETE ()

DQL(Data Query Language):

SELECT (we can ask questions. Selecting data and using it according to our requirement)


.

💾 Database

A database is simply an organized collection of related data that can be easily accessed, managed, and updated.
Think of it as a container or repository where data is stored — like tables in MySQL or files in a folder.

📘 Example:
Imagine you have a university database that stores:

  • Student records (name, roll no, address)

  • Courses offered

  • Marks and attendance

All this data together — stored in structured tables — is the database.

⚙️ Database System

A database system is a complete environment that includes:

  • The database (the data)

  • The DBMS (Database Management System) software that manages the data

  • And sometimes, users, applications, and hardware interacting with it

It’s the whole setup that allows you to create, manage, update, query, and secure your data efficiently.

📘 Example:
If your university uses MySQL to manage student data:

  • The MySQL DBMS software

  • The database files storing the student, course, and marks data

  • The hardware (server) running MySQL

  • The students, teachers, and admin apps using it

→ all together make the database system.




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