Difference between Ad-hoc & Exploratory testing

Ad-hoc is an informal test that can be carried out without referring to requirement specification documents for the application being tested. Ad-hoc tests primarily tests negative scenarios.
Exploratory is formal tests are carried out by experienced Software testers based on their previous testing expertise thereby test cases are designed during test execution.
There is no test case or scenario created during exploratory testing.
While exploratory tests, both positive as well as negative tests should be tested thoroughly.