For what purpose do low chimes often indicate during a flight?

Low chimes during a flight are typically used as an indication that the sterile flight deck period is ending and that normal operations can resume. The sterile flight deck is a critical phase where specific communication protocols are followed to minimize distractions, especially during takeoff and landing. When low chimes sound, it signals to the crew that they can now attend to non-essential activities such as servicing the cabin and interacting with passengers. This helps ensure passenger comfort and safety as the flight transitions back to a standard operational phase.