CocoaPods is a tool used to manage dependencies in Swift and iOS applications. It helps developers install third-party libraries, such as Alamofire for HTTP requests and SwiftyJSON for JSON parsing. To get started with CocoaPods, you need to create a Podfile, specify the dependencies, and then run `pod install` to link them to your project. The process involves creating a new Xcode Workspace and importing the libraries into your ViewController.swift file. With CocoaPods, developers can easily access APIs like NASA's Mars Rover API to load images from Mars in their iOS applications.