Question hdd case usb and windows

[cloudff7]

I use a USB 3.0 enclosure case + 2.5" HDDs. In Windows, there is an eject function that "safely removes hardware". When this function is finished, the HDD letter E: disappears from Windows. What is the situation and position of the magnetic disks and the read/write heads?

My HDDs are: 2013 models WDC WD10JPVX-08JC3T5, APPLE HDD HTS541010A99E662 and 2020 model Seagate ST500LM030.
The enclosure cases are: Orico 25PW1 black and Kesu 2530.