It is the primary testing after which further testing 
should be done. It helps reduce the time of testers. 
For eg in a LOGIN window, if it does not allow you to LOGIN 
no point in logging in,so we can go ahead with Basic 
Testing. This is also called Sanity Testing.

Conceptually Smoke testing and sanity testing both are same
but perception ally these are different.Smoke testing:Smoke
testing is conducted with negative perception it is the
testing in which all the functionality are available are not
is tested to proceed for further overall testing.Sanity
testing: This is also test for to check whether all the
functionality are available are not.But this testing is
conducted with positive perception.

some companies will say the sanity and smoke testing 
are same,but some companies will say just before releasing 
the build the developers will check whether the build is 
proper detailed testing(or)not.that is smoke testing
      once the build is released the test engineers will 
check the build is proper for detailed checking(or)not.that 
is sanity testing.

equivalence testing

Equivalence partitioning

Integration testing is testing different modules with in a
software system at once,,ieall the modules are tested as a
one whle software system

end-to-end testing is nothing but testing a product as and
end user to ensure whether it meets all requirements of end
user.

It defines about the bugs found by client to bugs found by 
tester

The no of defects identified in a component or system
divided by the size of the component of the system.

The Test Plan is the systmatic approch to do the testing of 
sofware where as The Test Strategy is the plan for how you 
are going to approach testing, plan of action to do the 
test. It is part of test planing

The Test Plan is schedule of list of activities like derived conditions, write and execute test cases, evaluate exit criteria as we as closer activities, whereas Test Strategy is how to derived test conditions. Basically Test Plan is what and when to do and Test Strategy is how to do testing.

In V model both testing and development activites happens 
parallely and at the end both joins at implementation 
phase. At each stage of V model V&V happens.

Acceptance Testing: Normally this type of testing is done 
to verify if system meets the customer specified 
requirements. User or customer do this testing to determine 
whether to accept application
Alpha testing:Testing is done at the end of development. 
Still minor design changes may be made as a result of such 
testing
Algorithm testing or Arc testing: Its a white box testing 
its nothing but  branch testing.
agile testing: Testing practice for a project using agile 
methodologies, such as extreme
programming (XP), treating development as the customer of 
testing and emphasizing the
test-first design paradigm.
accessibility testing: Testing to determine the ease by 
which users with disabilities can use a
component or system
ad hoc testing: Testing carried out informally; no formal 
test preparation takes place, no
recognized test design technique is used, there are no 
expectations for results and
randomness guides the test execution activity.

Severity is based on application point of view.where as,
Priority is based on Functionalities.

High severity and low priority (eg) wrong order of 
functionalities.
High prority and low severity (eg). spelling mistakes
System break/goes down comes under high severity.
High priority (eg). user interface bugs.

Severity is the seriousness of the defect or bug in terms 
of functionality.severity of a bug is technical in nature 
and Can be said to be how bad a defect is. 
Priority is the importance of defect in terms of customer's 
requirements.Priority is usually more of a business 
decision and would depend on the business objective of the 
application and how its owners see the bug.
1.High severity & low priority: 
If your software is to be released yet and you wil as a 
tester wil do some actions(which a normal user wil not do)
and which will cause runtime error in the application. This 
wil result in high severity but low priority as the 
application gave error its severe but as the particular 
action is generally not performed by a normal user its of 
low priority.
2. Low severity & High Priority
If you are testing a website and if u find a spelling 
mistake like wipra in place of wipro then its of high 
priority but low severity as it doesnt affect the basic 
functionality of the application but has to be corrected 
before release.
3. High severity & High Priority
If you are testing a application and if your application 
quits all of the sudden giving run time error this would be 
show stopper bug since you cannot proceed in further 
operations. This wud be high severity and high priority bug.
4. Low severity & low priority bug
defects like color combination, small spellings, grammar, 
overall cosmetic defects.

Severity: Means how often bug can break the application.

Priority : Means how can bug blocks the functionality.

Severity   Priority     Example

High        High        'Sign In' button is missing

High        Low         Rarely using link is giving some    
                        error message on access.     

Low         High        Cosmetic Error- Wrong spelling 
                        in logo 'Company Name'

Low         Low         Missing text on application

It can be like :
1.File having correct  format i.e. supported by the 
yahoo....
2.file containing correct data ...
3. file attached properly...i.e. whole data.
4.Empty file. etc

Basically, Test data refers to input provided to the test 
case for execution purpose.

I think the answer mentioned above is most qualified to be 
a pre-requisiste rather being a test data.

Test data could be:
1. Attachment file name - which would be used in the test 
case (test case for Yahoo attachment).
2. Attachment file location\path - which would be used in 
the test case (test case for Yahoo attachment)
3. Attachment file type (.i.e. doc,xls...etc)

For eg:
Testdata.xls should be available in the path :
d:\test\execution\testdata.xls

Found a defect,prepare a defect report with status : NEW

Defect accepted by development team status : open

Dev.team resolves the defect status : fixed/Resloved

If the defect is fixed status : close

If Dev.team rejects the defect status : duplicate.

Water fall model is a sequential step of processeds 
follewed. It starts with requirement gathering,analysis, 
design, coding, implementation, maintanence. You always 
finish one process and go to next. You cannot go backwards.

Spiral model mainly invloves risk analysis. You gather the 
requirements analyse the risk then you engineer the code 
and further implement. In a spiral the radius indicates the 
project cost and the spiral of the sector indicates the 
progress.