Alpha and beta testing - Software Engineering

Alpha testing:

Alpha testing is something we do after the all other testings at developers side i.e. Unit testing, Integration testing, system testing and etc when we are about to release the project to the market just before releasing the project we do this alpha testing.

Alpha testing is black box or white box? 

It can be any, depends on requirements sometimes it is white box and other times it is black box.

How to perform Alpha testing?

In alpha testing we create the environment in lab exactly like the real environment, and put the software on work and check if it is working fine or not. It is always at developers site

Beta Testing:

 It is some thing after releasing the project at the client side, developers have nothing to do with it, only client will run the project in the real environment and test if it is working the way it should and if some thing is wrong the client will report back to the developer.

Beta testing is black box or white box?

Keep it in  mind beta testing can't be a white box testing, if it is white box you can't count it as beta.

because in beta testing client checks the software on the basis of input and out put which is type of black box testing. You never give the access to client on code because a client do not know how to deal with program files that is why it can't be a white box testing.