What is data? | (Data Science ss : 1)

What is Data?

*Data is nothing but the collection of fact or individual unit of information. 

*There is Quality of data which is non numeric for example the cake is chocolaty, soft & cold. Quality of the data can be used to classy or categorize something; lets take an example : if we have a refrigerator filled with cakes we might collect cakes data which has weight of cakes with categories such as Chocolate, Blue Berry, Pineapple.

*There is also Quantitative data referring to a number for example the cake is 10 degree cold, weight 1kg & cost about $15. There are 2 difference type of Quantitative data :

1.) Discrete Data :

Discrete Data is a count which involve whole Numbers.

eg:

You can't have 1.5 kids or 2.36 dogs.

2.) Continuous Data :

It contains numerical data any value in certain range.

eg:

• Height
• Temperature
• Weight

*Data can be of different form such as primitive and non-primitive in which primitive data contains Boolean & Numeric in which integer, float, double etc is contained & in non-primitive string, Array etc is contained.

Okay...then we had seen what the data is; but almost 1 or 2 decade ago the data we had was divided in 3 parts :

• Small size
• Structured
• Single Format

*Small sized data : The size of data which was available back then was very small in compare to nowadays. The data was size of KB's (Kilobyte) or MB's (Megabyte). Those data we collected frequently & stored as an backup in case of data loss.

*Structured : Now what does it mean that the data was structured?...It actually means that the data was stored in rows and columns which made to utilization data very easy even nowadays we a well structured data is quite use full for us like we will be using .csv file for some machine learning purpose.

*Single Format : Back then the data was of the single format only which means the data was either be a text or a number.

Now as we saw that what data is and saw some details about what was data about 1 or 2 decades ago. Now let us see that from where all this data come's from.

Basically there are 2 sources of data :

• Primary
• Secondary

*Primary Data :

Now what do we mean by primary data? Actually primary data means the data which is collected by a researcher from first hand source, using methods like surveys, interview, or experiments.

*Secondary Data :

The term secondary data is very easy. If we relate it to the primary data i.e the data that is collected by someone from the reference of primary data is called as the secondary data.