manual testing : In manual testing u test each field in the 
application by entering multiple sets of data manually.It 
is a time taking process.

Automation testing : In AT u test the application with a 
software tool such as QTP etc without manual intervention.

MANUAL TESTING: Testing an application without taking the 
help of any automated tool such as winrunner, load runner, 
QTP etc.,, It takes more time. Much of human effort is 
required. Can't test the application throughly before the 
release. Takes much time for regression testing.

AUTOMATION TESTING: Testing an application with an help of 
some automation tool like winrunner, loadrunner, QTP etc.,
Runs test fast than human resources, can test application 
before its release. You can repeat the scripts N-number of 
times.

MANUAL TESTING:
tester conduct any testing on application build without 
using any tool.
AUTOMATION TESTING:
If any testing tool is used then it is called automation.

A tester conducts any test on application without using any 
tetsing tool is called manual testing.

A tester conducts any test on application with the help of 
testing tool is called as automation testing.

MANUAL TESTING IS A PROCESS OF TESTING MANUALLY BEFORE THE 
APPLICATION HAS RELESED 
AUTOMATION TESTING IS A PROCESS OF TESTING WHEN THE 
APPLICATION IS GIVEN

Manual testing: Tester will test, each test inputs 
separately in the application,without using any tools,which 
is a time consuming process,time consumtion is high.

Automation testing:Tool will give, multiple test inputs 
sequentially with the help of data driver wizard.time 
comsumption is low

Manual testing:Manual testing is nothing but the execution
of test cases manually and identifying the defects present
in the   AUT.In this we are executing the steps manually in
manual testing

Automation Testing:Executing the test cases with help of
automation tools like winrunner,qtp,load runner etc to
identify the defects present in the AUT(in automation
testing we are executing the test cases by recording the
steps to be executed with the help of tools)

and one more difference is manual testing is more time
consuming where as automation testing is very less time
consuming and its a 24*7 play

for manual testing human being presence is mandatory where
as for automation testing presence of human being is not
mandatory(optional)

Regards
Sm

Manual : It is done with out any help of the Software i,e. 
Test engineer directly test the application. In Manual 
testing we can Perform 100% job but, we couldn't assure the 
quality.The main thing is its not expensive.

Automation: It is done with the help of the Software(tools. 
In Automation testing we can't Perform 100% job but, we can 
assure the quality. It is highly expensive compare to the 
Manual..