A back-up system wold be anything that takes over in the event the main system fails. An example would be a back-up generator in case the power goes out.
A system backup is a copy of your computer data. It is usually the files you have saved on your computer but can also extend to other data such as your applications, settings, operating system and metadata.
backup
The metric IS the standard system in most of the world. Only a few countries hang back. And the reason that most countries have adopted it is that it is far simpler to use and more logical.
Hypoxic Drive
Anything redundant is a back-up system.
Synchronize Back-up System
because they had to back up other countries when they got in war
What Caribbean countries have a subway system?
the uk japan a LOT of countries, in fact. look up some countries on wikipedia and they should say which system they use in that country.
Anything redundant is a back-up system.
The Buddhists originally opposed the caste system but in Buddhist countries such as Japan similar systems were set up.