Conventions

In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows:

In the case of Ruby on Rails, these dependencies are found in Gemfile in Python requirements.txt, in Node.js package.json, and in Java pom.xml.

Any command-line input or output is written as follows:

$ heroku pg:info --app learning-heroku-postgres-app

New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "clicking the Next button moves you to the next screen".