Swift Package Manager (SPM) is a command-line tool for building, testing and managing Swift project dependencies. To get started with SPM, you need Xcode 8.0 or greater and Swift 3.0 or greater on OS X. You create a new directory and use the `swift package init --type executable` command to create a new Swift package. The Package.swift file is crucial as it defines the project name and dependencies list. SwiftyJSON is added as a dependency, and then you can fetch the dependencies using the `swift package fetch` command. After installing the dependencies, you can use them in your project by adding code to the main.swift file. You can build the project using the `swift build` command and run the executable to test it. Additionally, SPM allows you to generate an Xcode project, which provides benefits like autocompletion, making it easier to work with Swift projects.