What is the Install rail package?

There are several packages that you can download and install. The prebuilt Rails installer called Install rail which currently is only for Windows.

What is the log that has to see to check for an error in ruby rails?

Rails will report errors from Apache in log/apache.log and errors from the Ruby code in log/development.log. If you're having a problem, do have a look at what these logs are saying. On Unix and Mac OS X you may run tail -f log/development.log in a separate terminal to monitor your application's execution.

What is the use of super in ruby rails?
Ruby uses the super keyword to call the superclass (Parent class) implementation of the current method
What is the difference between nil and false in ruby?
False is a boolean datatype, Nil is not a data type it have object_id 4
What is the use of load,require, auto_load,require_relative in Ruby?

A method that loads and processes the Ruby code from a separate file, including whatever classes, modules, methods, and constants are in that file into the current scope. load is similar, but rather than performing the inclusion operation once, it reprocesses the code every time load is called. auto_load - Whenever the interpreter call the method that time only it will initiate the method in hat file.
require_relative - It it to load local folder files.