pre UAT testing: Before moving the build to the external 
server for the client reference, also called as alpha 
testing which is done in our organisation

UAT testing is beta testing

Hi,
  Pre UAT Testing is done by testing people as well as the 
business analyst before going to the production environment.

UAT Testing is done under the client place..

Pre UAT testing - This testing is done at the client 
location not by the client but by the people who has 
developed and tested the application. This is also known as 
alpha testing

UAT - Is user acceptance testing which is actually done by 
the client to see whether the system developed is as per 
the requirements given by them and is fulfiled or not. This 
is the last phase of SDLC and is also known as beta testing

We can say.....

Pre UAT -- Alpha testing
    UAT -- Beta testing

Rasul
QA Engineer
rasul_Cse@yahoo.com

Pre UAT test is nothing but alpha testing, it done by 
inhouse people(Business analyst..) in client place before 
going to the market.

UAT test is nothing but beta testing it is done by end 
users at real time environment. here product is in market, 
take the bugs and suggesions from end users.