Question about flash write on ESP8266

Hello,

from reading the docs, I couldn’t get a definitive answer.
Are only globals stored in flash, or also any sensor data (entity states)?
Are only values stored in flash which are explicitly assigned the “restore_value: yes”, or are all values stored when “esp8266_restore_from_flash: true” is defined in the board parameters?

If I understand this correct, in the following example config, only the “global_1” is written to flash, right?

esphome:
  name: node_1
  platform: ESP8266
  board: nodemcu
  esp8266_restore_from_flash: true    #enabling storing in flash

globals:
  - id: global_1
    type: float
    restore_value: yes  #this is the only global I want to restore from flash
  - id: global_2
    type: float

sensor:
  - platform: ultrasonic
    id: sensor_1
    trigger_pin: D1
    echo_pin: D2
    update_interval: 60s

Thanks in advance to anyone who can shed some light on this.

I’m reading the docs and half the internet almost two years later and still can’t figure it out. Must be a taboo subject.