operator overloading,uffer overflow and memory leakage,multi threaded and concurrency

1) Operator overloading is to allow the same operator to be bound to more than one implementation. In C++, the mathematical, logical, relational operators are already overloaded for built-in data types. In order to use these operators with user-defined data types such as classes, we have to overload these operators. In java, operator overloading is not allowed.

2) Object based programming language is a language that does not support all the concepts of Object oriented programming such as inheritance and polymorphism. Object based programming language uses object but does not support inheritance and polymorphism whereas object oriented programming language supports all the concepts of object oriented programming. Java script and VB (Visual Basic) are object based languages whereas Java, C++, C# are object oriented languages.

3) Static binding occurs at compile time whereas dynamic binding occurs at run time. The static binding is the concept of resolving function call at compile time. With static binding, the function call is bound to specific memory location where the function will be placed at compile time. Dynamic binding is the concept of resolving function call at run time. With dynamic binding, the function will be placed at run time. It is known at run time that which function is being called.

4) Buffer overflow condition occurs when we attempt to store the data beyond the boundaries of buffer. When overflow occurs then either run time error occurs or the data is stored beyond the boundaries of buffer.

Memory leakage occurs when memory is allocated from heap but is not allocated when memory is no longer in use. In Java, it is not the responsibility of programmer to release the memory as it is performed by Garbage Collector. Memory management in java has been taken away from programmer.

5) Web applications are stored on a web server and delivered to users over the Internet. Web application is deployed in web server which has web container.
Web applications are developed using JSP, Servlets, Java,...

Enterprise application is delopyed in Application server which has Web container, EJB container, etc
Enterprise Applications are develpoed using JSP, Servlets, Java, Web Services, EJBs, etc
6) Multithreading is the ability to do multiple tasks concurrently. The concurrency is the property in which multiple components (threads) are executing and overlap in time, it means multiple threads do not execute simultaneously but are interleaved in small slice time. A program is said to be concurrent in which multiple components are executing at once. A program without multithreading executes sequentially.

7) The Java Archive (JAR) file format enables you to bundle multiple files into a single archive file. Typically a JAR file contains the class files. The JAR files are packed with zip file format.

Garbage Collector: Java performs garbage collection and eliminates the need to free objects explicitly. When an object has no references to it anywhere except in other objects that are also unreferenced, its space can be reclaimed.
Before an object is destroyed, it might be necessary for the object to perform some action. For example: to close an opened file. In such a case, define a finalize() method with the actions to be performed before the object is destroyed. When a finalize method is defined in a class, Java run time calls finalize() whenever it is about to recycle an object of that class. It is noteworthy that a garbage collector reclaims objects in any order or never reclaims them. We cannot predict and assure when garbage collector will get back the memory of unreferenced objects.
The garbage collector can be requested to run by calling System.gc() method. It is not necessary that it accepts the request and run.