You cannot use keywords, like public , class and void as variable names. So far, the statements we have seen are declarations, assignments, and print statements. A statement that creates a new variable and determines its type. A statement that assigns a value to a variable. A combination of variables, operators and values that represents a single result value.
Expressions also have types, as determined by their operators and operands.
A special symbol that represents a simple computation like addition, multiplication or string concatenation. One of the values on which an operator operates. The order in which operations are evaluated. The ability to combine simple expressions and statements into compound statements and expressions in order to represent complex computations concisely.