But , What exactly the Pattern Recognition is ? : Pattern Recognition definition and basics. (Updated)

Pattern in General

A pattern is the similarities found in things, or we can say that the things of the same type have some similar or some common features or characteristics that's why they are similar.

Let's take an example and understand the actual meaning of pattern with the daily use things :

We eat fruits daily, they are of different kinds.
ex. - Apples, Bananas, Mangoes etc.
But how can you say that the fruit we are eating is an Apple .
We can say that by looking at the fruit, if it matches(looks) like an Apple then sure it is an Apple.
Now the question arises that why we should say that the fruit is an Apple:
"We have created a group of all the fruits that have similar features called Apple." Here the name Apple is the class of all the objects (Apples).

Pattern Recognition (Definition)

The definition of Pattern Recognition (PR) :

• Pattern Recognition is one of the subsets of Machine Learning.
• The process of identification of patterns in a group of objects.
• The process of finding (identification) of similarities or regularities in the given data , is called as Pattern Recognition. 
• Pattern recognition is the ability to detect arrangements of characteristics or data that yield information about a given system or data set. ... In the context of AI, pattern recognition is a sub-category of machine learning (ML).
• The field of pattern recognition is concerned with the automatic discovery of regularities in data through the use of computer algorithms and with the use of these regularities to take actions such as classifying the data into different categories. (from C.M. Bishop's Book)

• We have found that all the apples were in similar shape.

• The shape was the pattern for them to fall into the same class.

• We have also found the pattern on the Televisions, Mobile Phones and all the other things that look similar.

Pattern in Data

The world is full of data and most of the data has patterns (similarities) in it.
To mine (or simply understand) the data we need to find those patterns.

DATA : 

     Data is the collection of facts about any object they can be anything the measurement, color weight, etc.

Some of the objects can be having similar measurements, the number of legs of a table.

Example: all the Tables have 4 legs and a flat surface placed(fixed) on them. 

So we can define the pattern in data as : 

The similarities or regularities found in a collection of the data (simply called data-set) are called as pattern in the data-set.