Hi there,
So Often this term comes up " RTOS "
Real-Time Operating System
What is it ?
A Real-Time Operating System (RTOS) is a specialized software designed to manage and execute tasks in real-time applications.
A Real-Time Operating System (RTOS) guarantees that tasks are not only completed but executed within strict timing constraints, making it critical for fields like aerospace engineering. It manages a microcontroller’s time by efficiently sharing the processor among various tasks. Many modern microcontrollers use an RTOS, such as the modified FreeRTOS on ESP32 or the Zephyr OS adopted by Nordic. However, some application-specific IoT devices may operate on bare metal without an OS.
Zephyr is One… The characteristics of an RTOS are tailored to address the unique demands of real-time applications. Real-time task scheduling, minimal latency, and precise timing are fundamental features that set an RTOS apart.
Here is Info on said subject that will assist you.
RTOS
Today Zephyr has become the leading open source RTOS for connected IoT devices. With developers worldwide, support for numerous architectures and a thriving ecosystem, in its short 10 year history Zephyr has evolved into a de facto industry standard.
HTH
GL 
PJ 
ask any questions you may have, I will update this and other threads as the information comes out in an effort highlight the fundamentals and basics while trying to stay current in this EVER changing field.
AS- YOU were. 