Key Concepts

Question 1

What is Java?

Answer 1

Java is one of the most popular programming languages. It is classed-based, object-oriented and easy to learn.
It is also an execution platform.

Question 2

Why Java is so popular?

Answer 2

1 - It is platform independent which means I program compiled in java can run in any OS. (Write Once Run Anywhere)
2 - It is user-friendly.
3 - It is used by a lot of big companies world-wide.

Question 3

Wht are the Advantages of Java over other programming languagues?

Answer 3

1 - Static types (Easier to read and provide better IDE support)
2 - Ecosystem
3 - Strictness (Java does not forgive you)
4 - Plataform independently
5 - It has a good built-in library
6 - Concurrency features.

Question 4

What is JDK?

Answer 4

JDK is a software development environment used for making applets and Java applications. The full form of JDK is Java Development Kit.

Question 5

What is JRE?

Answer 5

JRE is a piece of a software which is designed to run other software. It contains the class libraries, loader class, and JVM. In simple terms, if you want to run Java program you need JRE.

Question 6

What is JVM?

Answer 6

JVM is an engine that provides a runtime environment to drive the Java Code or applications. It converts Java bytecode into machine language. JVM is a part of Java Runtime Environment (JRE). It cannot be separately downloaded and installed. To install JVM, you need to install JRE. The full form of JVM is Java Virtual Machine.

Question 7

What is the classpath?

Answer 7

Classpath is a parameter in the Java Virtual Machine or the Java compiler that specifies the location of user-defined classes and packages.