system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: We all heard the line on computers shutting down when we were younger "if you just cut the power, you will corrupt the hard disk". Why is that? Is there something that facilitates that corruption? And why is it so much less common nowadays than in days gone by?
gpt
The corruption occurs when the hard drive is in the middle of writing data to a file (potentially a critical system / configuration file) and the power is shut off before the remaining data can be written. 

When the computer / operating system then attempts to open and read the file later, data will be missing and some of the data may be prematurely terminated. This potentially cause the system to crash, and at the very least will likely prevent the software/OS from reading and processing the file normally.