What is Monkey, Sanity, Smoke, Gorilla and Adhoc Testing?

Gorilla Testing : Testing one particular module,
functionality heavily

Smoke Testing: Smoke testing is done at the start of the application is deployed. Smoke test is the entry point for the entire test execution. When the application is passed under the smoke test then only further system testing or regression testing can be carried out.
In general smoke testing is done when the higher version of the build is deployed and is done at each and every time the build is deployed. In smoke testing the main functionalites are tested and the stability of the system is validated.

Sanity Testing:Sanity testing is also similar to Smoke testing, but has some minor differences. Sanity testing is done when the application is deployed into testing for the very first time and in smoke testing only positive scenarios are validated but in sanity testing both the positive and negative scenarios are validated.

For example, if the new software is crashing systems every 5 minutes, bogging down systems to a crawl, or destroying databases, the software may not be in a 'sane' enough condition to warrant further testing in its current state.

Ad-hoc testing :Testing carried out using no recognised Test Case Design Technique which is a method used to determine Test Cases. Here the testing is done by the knolwedge of the tester in the application and he tests the system randomly with out any test cases or any specifications or requirements.

Monkey testing:
Monkey test is a unit test that runs with no specific test in mind. The monkey in this case is the producer of any input. For example, a monkey test can enter random strings into text boxes to ensure handling of all possible user input or provide garbage files to check for loading routines that have blind faith in their data.

What is Functional Testing?
Testing the features and operational behavior of a product to ensure they correspond to its specifications. Testing that ignores the internal mechanism of a system or component and focuses solely on the outputs generated in response to selected inputs and execution conditions. or Black Box Testing