system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:What will happen if I don't "eject" my flash drive before taking it out?
gpt
The whole ejecting of removable media centers around write buffering. Modern operating systems save up a bunch of writes and then blast them all to the media (usb drive, disk etc.) all at once - it makes writing to the media more efficient.

Choosing the "eject" option "flushes" all pending writes (i.e. forces the writes to happen; and also closes any files that may be open), ensuring you dont lose any data.