Notification alerts are messages that inform users about important updates or events on their devices. These alerts can come from various applications, such as email, social media, or calendar apps, and are designed to grab the user's attention. They can appear as pop-up messages, sounds, or vibrations, depending on the device settings. Users can customize notification alerts to prioritize which messages they want to receive. For example, they may choose to receive alerts for text messages but silence notifications from news apps. This customization helps users manage their time and focus on what matters most to them.