Build is an executable file that refers to that part of an application that is handed over to a tester to test the implemented functionality of the application along with some bug fixes. The build can be rejected by the testing team if it does not pass the critical checklist which contains the major functionality of the application.
There can be multiple builds in the testing cycle of an application.
Release refers to the software application which is no longer in the testing phase and after completion of testing and development, the application is handed over to the client. One release has several builds associated with it.
