This tutorial provides a detailed guide on building a simple Contact Card mobile application using Xcode 9 and Swift 4, focusing on creating UI constraints programmatically without Storyboards or NIBs. It emphasizes the use of the PureLayout library to simplify the process of setting constraints, allowing for efficient and clean code development. The tutorial walks through the setup process, including initializing a new project, installing PureLayout via CocoaPods, and configuring the UI components such as an ImageView, a UIView, a segmented control, and an "Edit" button, all while ensuring proper layout and hierarchy in the interface. It also covers techniques like lazy variable initialization for optimizing memory usage, using the eight-point grid system for consistent spacing, and managing the view stack to ensure correct display layering. The tutorial encourages experimentation and practice by suggesting readers recreate application views to enhance their skills, setting the stage for part two, which will expand on this foundation by adding more complex UI elements like a navigation bar and table view with dynamically-sized cells.