Theory:

Imagine us planning a field trip. As soon as we finalize on the destination, we collect names of those willing to join us for the trip.
 
The collected list of names is the data.
 
Data:
Data is a collection of information.
Example:
1. A name list
 
2. States of India
 
3. The list of patients in a hospital
Types of data:
 
We can classify data into two types based on the mode of collection as primary and secondary data.
 
Primary data:
When we collate data for the first time, then it is called primary data.
Example:
1. Collection of information about each person's favourite pass-time.
 
2. Groceries list for the upcoming month.
 
3. List of upcoming railway routes in India.
Secondary data:
When we perform collation and analysis on an existing data, then it is called secondary data.
Example:
1. The list of registered voters in the region.
 
2. The list of students in primary grades.
 
3. The number of MTC buses plied every day of the month.