I will use this article to point out some of the cornerstones of Java as a programming language because any programmer has to start learning them. This set of concepts is very important for any Java programmer who needs to be able to build working applications. In other words, we will be looking into variables, data types, and operators. To an extent that may appear as a crass simplification, these topics are the linchpins in comprehending Java at a more nuanced level.

As an English instructor whose students are participating in a course that is designed to enhance their grasp of Java, I would like to say that the technicalities of the language can be simplified, broken down into smaller and easier parts. By the end of the article students are expected to be able to use variables, data types, and operators since they are some of the most basic functions in Java programming.

1. Variables: Getting Started

In Java, variables serve as storage for values that your software will be able to use. In a nutshell, a variable could be seen as a bucket in which an amount of data like a type or a figure is kept and can be retrieved once needed in the program. It is necessary to mention, however, that Javas have to first reserve a space for the variable before they can use it. This reservation comprises the variable's name and its data type which are two aspects.

A variable name is a label you assign to a piece of data. It is similar to giving a name to a folder or file on your computer so that you do not have to search for it at a later stage. The content or type of data stored in the variable must be reflected in the variable name. For example, if the age of a person is stored, say a `sex`, the variable may be referred to as 'age'.

It is important to note that there are some rules for naming variables in Java:

- A letter, a dollar sign (`$`), or an underscore (`_`) is a valid starting character.

- A combination of letter numbers, dollar signs, or underscores would be acceptable.

- Java identifiers (reserved words that have specific meanings in the language e. g `int` and `class`) cannot be variable names.

Variable naming is just one half of the equation, it's crucial to identify its data type. A data type gives definitions to the kind of data that the variable can accept for instance, integer, decimal, or a character. We however would elaborate on the occasion on types of data in our subsequent section.

2. Data Types in Java

The types of data that can be stored in a variable is called data type, so in a nutshell, a Java variable will declare/data type. [...] Java is considered a strongly typed language, this means a variable in Java is assigned a data type, every time, and cannot use values that don't belong to this data type. It is clear before working with JAVA for instance, it defines a number of primitive data types so it will be useful to know what the majority of them are.

Broad enclosing two main categories of data types in Java, there are primitive types and reference types. We can start scanning each other's memories by initializing with Java's primitive data types.

2.1 Primitive Data Types

In Java, there are 8 primitive data types built into the programming language, those include;

1. int An int data type is very useful for storing integer values (whole numbers). You might want to use `int` to save the age of a person, for instance.

2. double A double data type is used to hold decimal (real) numbers. This type of data is suitable when one needs to store values with a higher degree of accuracy such as a person's weight and the temperature.

3. float : This data type is very similar to the double as both are used to represent numbers. The only difference is in degrees of accuracy. Unlike double precision, float does have a smaller area of application as it stores numbers with lesser accuracy, thus consuming less memory.

4. char : This type is used for storing a single character, for instance a letter or a symbol. For instance, s`char` can be utilized to be a person's first initial.

5. boolean : A `boolean` variable can only take on one of two values – either true or false. This data type is very important in controlling the different branches within the program.

6. byte : This data type is used to Shrink integer numbers, where a byte is represented by 8 bits and holds a range of values from -128 to 127.

7. short : This type's memory consumption is lower than integers at 16 bits and it also encompasses a lesser range.

8. long : It is specifically useful for large integers and typically resides in 64 bits of memory along with huge numbers.


With these considerations in mind, all of these primitive types are made up of different kinds of data. Also, one should always choose the most appropriate type for the particular variable while writing a program to avoid efficiency and accuracy problems.

2.2 Reference Data Types

Apart from primitive data types, there are also reference types in Java These are used in order to refer to the given objects. In other words, every object is an instance of a class which serves to blueprint the objects to be created. Among other elements, classes, arrays and interfaces are also examples of reference types. Reference types differ from primitive types in that they do not contain the actual data but rather a reference or pointer to the data.

So, for instance, a `String` is a reference type in the Java programming language. It denotes a sequence of characters in such a way that it can represent a person's name or a sentence. For instance, a `String` variable is created, which will hold the reference to the object holding the actual sequence of characters.

3. Operators in Java

Now that we have known and understood what variables and the various data types are, we now proceed to operators. In computer programming languages including Java, operators are In symbols or keywords that are used to perform operations on the defined variables and values. They are vital in relation to arithmetic calculations, values comparisons, and data manipulation in all your programs.

Java provides various kinds of operators, which we shall divide into the groups below:

3.1. Arithmetic Operators

Arithmetic operators are used to carry out basic arithmetic operations on numerical values. These include addition, subtraction, multiplication, division and modulus (remainder after division).

The arithmetic operators in use in Java include:

- `+` (Addition): It combines the value of two numbers.

- `-` (Subtraction): A number is deducted from another.

- `` (Multiplication): Two numbers are multiplied.

- `/` (Division): A number is divided by another.

- `%` (Modulus): It provides the remainder after dividing two numbers.

For example, if two integers are divided, the resulting integer will not have a decimal value and any fraction will be ignored.

3.2. Relational Operators

A Relational operator compares two values and defines the relation between both. These are important especially when decisions are to be made in your program in relation to the two values.

The relational operators in use in Java are:

- `==` (Equal to): Determines if two numbers have the same value.

- `!=` (Not equal to): Determines if two numbers do not have the same value.

- `> ` (Greater than): Determines if the first value is more than the second value.

- `<` (Less than): Determines if the first value is less than the second value.

- `> =` (Greater than or equal): Tests if one numerical value is larger than or equal to another.

- `<=` (Less than or equal): Tests if one numerical value is smaller than or equal to another.