The right side to a semi tractor trailer is their huge blind side, meaning the driver can't see you, and may merge lanes with you, thus crashing into you.
All server side errors start with 5XX
It really depends on your type of data, if it's sensitive data or not. And it also depends on what type of backup (Incremental, Decremental, etc.). But you should aim to backup at least once a week, and also do a backup of your original backup.
The Function of a header is that it makes your TEXT LOOK BIGGER
We need more information for this one, please.