hai...........its not a bata testing its spell missed ist 
beta testing.......
the diffrnec between the alpha testing and beta testing are
alpha testing is  nothing but an user acceptance testing 
done by the client at developement site..............beta 
testing is aslo a user acceptance testing done by the end-
users at client site.sanity testing is nothing but an 
system testing........here the testers test the basic 
functinalites of the application to know weather the 
application is applicable for  futher testing or 
not..........
if any thing wrong plz let me know