Does cucumber do away with the need to write unit tests?

Question

I am a little confused by the sheer number of testing frameworks available for Ruby/ROR.

I have recently watched the Cucumber Railscasts and found them very interesting.

Answer 1

When a unit test fails (I mean a real unit test that tests a method in isolation using mocks), it tells you what "unit" has a problem. When an acceptance test fails, it tells you what "feature" has a problem, not where the problem is located.