The "Watch Series" refers to a collection of smartwatches developed by Apple. These devices combine traditional watch features with advanced technology, allowing users to track fitness, receive notifications, and access various apps directly from their wrist. The series has evolved over the years, introducing new health monitoring capabilities and improved performance. Each generation of the Watch Series offers different models, catering to various preferences and budgets. Users can customize their watches with interchangeable bands and watch faces, making it a versatile accessory for both everyday use and special occasions. The integration with iOS devices enhances its functionality, making it a popular choice among smartphone users.