Exploratory testing means testing the process without any 
specific plans and schedules.

u can say that its a one type of informal, creative testing 
not based on test plans or test cases. Testers may learn the 
software as they test it.

Exploratory Testing is an informal testing which is used to 
gain familiarity of the application.

When a tester test a application by exploring with his 
previous experience and based on the application tester 
writes test cases. This is exploratory testing

Suppose we didn't having any testing documents that r related 
to our application...and also we don't know the functionality 
of the application ...then this time we go for exploratory 
testing...in this type of testing we know the functionality 
of the application..

Exploratory testing  is an interactive process of 
concurrent product exploration, test design and test 
execution.

The tester designs and executes the test cases while 
learning the product.

Exploratory testing is useful when:

1. you are asked to test something on short notice.
2. test early in development process.
3. in situation with minimal document.

When a tester test a application by exploring with his 
previous experience and based on the application tester 
writes test cases. This is exploratory testing

It is the formal testing where we dont use test plan and 
test cases.when we get an application we have learn that 
application and we have to test by using our creative 
knowledge.

its a type of testing in which usally domain expert will 
perform the tg on the application parllaly tester will test 
the application without having the knowledge and 
requriments

It is basically a formal type of testing which is performed
(prefered) by an experienced person,the one who is well 
familiar with the application and can hit the right areas 
while testing.It is done to save time and very useful in 
crunch situation.A better way of performing exploratory 
testing is to form a quick structure of high scenarios 
which highlight the areas under test to track it easily 
once the testing is completed.This way exploratory testing 
is effective.

exploratory testing is aslo an informal type of testing is 
done when the application doesn't have the deatailed 
inofrmation abut the build at this suituation the tester 
will start explore the things present in the application 
and aslo simulteanoulsy tester will learn the things 
present in the application is called exploratory testing.