What are STRINGS and why can I not delete the file?

[Hikermann]

I use a Seagate external drive for my backup; there is a file called STRINGS (e.g., Strings\3a0729826d2c1d047c0b55); what are these and why can they not be deleted (they're from 2013)? Thank you.

 

[DelJo63]

Likely the Strings\ is under Windows or Windows\system32 and that makes them system files.