Is tester execute set of regression test cases may called as batch test ?
Batch testing is having a bunch of coded tests and running them all at once, whereas manual testing would be picking a test and running it individually. It is almost always better to have batch tests, because that lets you validate builds with batch testing and easily to regression testing.
Depends on who you talk to. Context matters, as different shops may use different terminology. For example, on one project, they used the term 'test plan' to refer to what I would call a test case, and 'master test plan' to refer to what I would call a test plan. I have often seen 'batch testing' to refer to the testing of batch processing in your application. For example, if your application generates a set of reports nightly/weekly/monthly in a batch process, testing that feature could be called batch testing.