A brief theory: features and applications of Java
Java was developed by Sun Microsystems in the early 1990s. Canadian engineer James Gosling played a leading role in the creation of the language, and in the early stages of development the language was called Oak. Then it was renamed after Java coffee, and the cup in the logo was named after it.

James Gosling and his associates wanted to create a language with a C-like syntax. At the same time, it should be simpler than C/C++. The creators planned to use Java for programming consumer electronics, but almost immediately after the release of version 1.0 in 1995, the language began to be used by developers of server and client software.

In 2010, Sun Microsystems was bought by Oracle. After that, James Gosling moved to Google, from which he also soon quit.

Features of the Java language
Java is a general-purpose programming language. It refers to the object-oriented programming languages, languages with strong typing.

Its founders implemented the WORA principle: write once, run anywhere, or “write once, run anywhere”. This means that an application written in Java can be run on any platform as long as it has a Java Runtime Environment (JRE) installed.

This is accomplished by compiling the code written in Java into byte-code. This format is executed by the JVM or Java Virtual Machine. The JVM is part of the Java Runtime Environment (JRE). The virtual machine is platform-independent.

Java implements a memory management mechanism called garbage collector or garbage collector. The developer creates objects, and JRE uses the garbage collector to clear memory when the objects are no longer in use.

Java’s syntax is similar to that of other C-like languages. Here are some of its features:

case sensitivity – User and user identifiers in Java represent different entities;
LowerCamelCase is used to name methods. If a method name consists of one word, it must begin with a lowercase letter. Example: firstMethodName();
UpperCamelCase is used for naming classes. If the name consists of one word, it must begin with a capital letter. Example: FirstClassName.
The name of the program files must exactly match the name of the class, taking into account case sensitivity. For example, if the class name is FirstClassName, the file should be called FirstClassName.java;
identifiers always start with a letter (A-Z, a-z), a $ sign, or underscore;

What’s written in Java: Applications
According to Oracle, Java programs run on 3 billion devices. For example, the vast majority of large companies use Java in one way or another, and a lot of corporate server applications are written in Java. For example, we are talking about programs for financial institutions, which provide transactions, fixing trade transactions.

Many web applications are also written in Java. Popular frameworks, including Spring, Stuts, JSP, are used to create a variety of applications on the web: from ecommerce projects to large portals, from educational platforms to government resources.

The popular computer game Minecraft is written in Java.

Mobile development is another use of Java. Applications for devices running on the Android operating system are written in this language. Java is also used to create client applications.

In addition, Java is used to work with Big Data, developing programs for scientific purposes, such as natural language processing, programming devices – from household devices to industrial plants.

That is, different types of applications can be written in Java: web, mobile and desktop software, games, and so on. Traditionally, this language has a strong position in industrial programming, in the segment of large companies.