Question d’entretien chez Cognizant

As my programming language was java so they asked java specific question like. 1. Is java platform independent? 2. Why java do not support multiple inheritance? 3. What is JVM, JRE, JDK? 4. What is java servlet? (i was not able to answer this question) 5. How we connect Sql with JDBC? (i was not able to answer this question)