Devise Gem

gem 'devise' --> authorization and authentication

Authentication
-logged into the system enables you to do functionalities in the system

Authenticated
-are you authorized to do A, B or C
-administrator of system or viewer of data

User
email (string)
enrcypted_password (string)

Authorization

rails generate devise:install
-migration file for model called user.rb
-what makes this unique is it makes user with email and encrypted password

rails generate model User

before_filter :authenticate_user! -- put inside controller

Controller_authentication
-before filter

View authentication
-user_signed_in?

1. rails g devise User
2. authenticate controller by adding before filter