The AWS Command Line Interface (CLI) is a command line tool provided by AWS to manage AWS services. You can save your credentials and config into profiles, and then specify a profile while executing a command. The more you get familiar with the CLI commands, the faster you can work with AWS services, making you more productive. 

In this recipe, we will deploy an AWS Lambda using AWS CLI. We will use an updated hello world. In the last recipe, we had sent and received back simple text. In this recipe, we will demonstrate the use of POJOs for sending to and retrieving JSON data from the Lambda handler. 

In most of the later recipes within this book, I will be including AWS CLI commands along with either Management Console or CloudFormation steps to provide an overview of various API usages in a programming language-independent way. You can follow these API usages along with any particular programming language SDK documentation to implement it in that language. The CLI commands also help us better understand the CloudFormation templates.