Something that used in an expression to manipulate objects such as + (plus), - (minus), * (multiply), and / (divide). You can also use operators to do comparisons, such as with <, >, and &&. The priority is based on "BODMAS"
Symbol are same like string but both behaviors is different based on object_id, memory and process time (cpu time) Strings are mutable , Symbols are immutable.
Float class is used whenever the function changes constantly. It acts as a sub class of numeric. They represent real characters by making use of the native architecture of the double precision floating point.
Max is used whenever there is a huge need of Float.
Dig is used whenever you want to represent a float in decimal digits.