A binary operator has two operands E.g., +, -, *, /...  In most languages, binary operators are infix, which means they appear between their operands  There are also operators that are prefix, i.e., they precede their operands.
 usually done explicitly as a request from the programmers e. g Java can convert int to short one needs to process the int value in a method design to work with short values.  The conversion is not safe (overflow may happen).
 Relational operator is a binary operator that compare the values of its operands and the result is a Boolean value True or False.  eg “Not Equal” operator could be one of these:!=,/=, ~=,. NE. or <>.
 expression eval' where the result is determined w/out eval'ng all of the operands and/or operators  (a>=0)&&(b<10) if (a<0), because (False && (b<0))is False for all value of b. Therefore, there is no need to evaluate (b<0)