What do you understand by ruby and ruby and rails?

Ruby : It is an object oriented programming language inspired by PERL and PYTHON. 

Rails: It is a web application framework which is written in ruby language and is developed by David Hansson. It is an open source ruby framework for the development of database backend web application. It consists of everything which is needed for creating a database driven web application with the help of model view controller pattern.

Ruby on Rails or Rails is a model-view-controller, server-side framework which is written in ruby. It provides a default structure for a database, web service and web pages. It makes use of web standards like JSON, XML, HTML, CSS, etc. for the transfer of data and also for displaying and user interfacing. It was developed by David Heinemeier Hansson on 13th December 2005. It even uses various software engineering patterns and paradigms some of them being- Convention over configuration (CoC), Don’t Repeat Yourself (DRY), Active Record Pattern (ARP). It had a great influence on the web development since it had some innovative features and frameworks.

What is meant by Object Oriented Programming?

Object-oriented programming (OOP) is a style of programming characterized by the identification of classes of objects closely linked with the methods (functions) with which they are associated. It also includes ideas of inheritance of attributes and methods.

The simplest way to explain object-orientated programming to a kid is to use something like a car as an example. A car has a model name, a colour, a year in which it was manufactured, an engine size and so on.