i. Variables are named storage location to store values temporarily which can be changed during program execution.
Data type states the way the values of that type are stored, the operations that can be done on that type and the range for that type.
For example:
int marks;
In the above statement, int is the data type and marks is the name of variable which store values temporarily.
ii. Assignment operator (=) is used to assign any value in a variable/constant while comparison operator (= =) is used to compare values.
For example:
int marks=90;
In the above statement value 90 is assigned to the variable named marks.
if(marks==40)
jTextField1.setText(“Just Pass”);
In the above if statement, value of marks is being compared with 40.