One of the fundamental aspects of Object-oriented programming is inheritance. Inheritance lets a class inherit properties from another class. Child class acquires behaviours from its parent class. This means the child classes will automatically have parent class methods, without having to implement them.

We use inheritance to keep common behaviors in a parent class and share with child classes. This way we can keep common logic in one place. Ruby support single inheritance

Example:

class Person
  attr_accessor :name, :dob, :address

  def initialize(name, dob, address)
    @name = name
    @dob = dob
    @address = address
  end

  def profession
    "Nothing"
  end
end


class Teacher < Person
  def profession
    'teaching'
  end
end


class Doctor < Person
  def profession
    'doctor'
  end
end


a = Doctor.new("ravi", "4 Nov", "India")
a.name # => "ravi"
a.dob # => "4 Nov"
a.profession # => 'doctor'

Here the Parent class is super class. Teacher and Doctor classes are inheriting from Parent class. Child classes acquire behaviors  (initialize, getter and setter methods)  from its parent class. We have overridden "profession" method in child classes.