Selections determine the quality and flexibility of almost every edit you make in Photoshop. Three modern tools — the Object Selection tool, Remove Background with Harmonize, and the Selection Brush — handle the most common selection tasks with far less manual effort, while keeping your original image intact through non-destructive layers.
Read the full article here: How to Use Object Selection, Remove Background, and the Selection Brush in Photoshop Photoshop Roadmap