New to these forums, if I am on the wrong channel, please let me know where.
Pretty new to PIO, but in the “hello world” of the espidf framework. Going through the tutorials Get started with ESP-IDF and ESP32-DevKitC: debugging, unit testing, project analysis — PlatformIO latest documentation and in the code section, I see where it is init the nvs, but I never see where they read or write to it. It could be needed in the tutorials and I missed it or it is a requirement of setting up a softAP wi-fi. Just curious.
If you have questions regarding ESP-IDF programming, the better place would be official Espressif forum.
The non-volatile storage is used internally in ESP-IDF to e.g. store the last WiFi credentials (if configured to do so) and PHY calibration data (WiFi radio settings). This is e.g. accessed through nvs_open here. This forum post hints at the same. So, the WiFi subsystem likely needs the NVS.
ESP-IDF is an incredibly big framework, with many things happening behind the scenes.
My subject title may have been a poor choice. I was curious what the tutorial which is a PIO example init it without accessing it. Your suggestion did cause me to did into Espressif website and I found the doc. I going to assume the wifi needs it. I found this Wi-Fi - ESP32 - — ESP-IDF Programming Guide latest documentation
So I rem out the nvs initialization and did get an error.
When I am trying to learn something new, I hate mysteries. 
And I learned some more resources. Thanks.
For anyone else who comes across this thread…
