Hi all
Chandu's answer is absolutely perfect. I'll add some stuff to that.
Generally test plan is prepared by Test Lead depending on the above mentioned points and Test strategy. Depending on the test strategy test lead prepares Test Plan. Test engineers can be involved in creation of test plan. like estimating time to complete the assigned tasks project duration project cost etc.
Test cases are developed after analysis of Busines Requirements/ Business design documents.
Suppose gmail is our project.
1. In BDD we have like user name should be only alphanumerics
Depending on this requirement we'll prepare test data and test cases.
cheers
dileepkumar.g@gmail.com