How do downloads get Corrupted

[Kai Reinko]

I would like to know and can't seem to find the answer to :how do downloads get corrupted? I am sure there are many variables but a few examples would be nice since i can't seem to find anything listed as such anywhere on the web, to better my understanding of ways that downloads can get corrupted and how to prevent it from happening or fix it. Use examples in :how it happens, how to prevent, how to fix. Thank you.

 

[Colif]

Hard drive could be damaged
Ram could have faults that corrupt the data on the PC as it is stored in ram
LAN drivers could be old and in need of replacment
Source file could be corrupt before you download it

Probably others I can't think of