---
title: "Backup vs. Back Up, Failover vs. Fail Over, Failback vs. Fail Back"
description: "Backup is a noun spelled as a single word, while back up is a verb spelled as 2 words. Failover is a noun spelled as a single word, while fail over is a verb spelled as 2 words."
canonical: "https://helpcenter.veeam.com/docs/styleguide/tw/backup_failover_failback.html"
breadcrumb: "Style Guide > Tips and Tricks > Backup vs. Back Up, Failover vs. Fail Over, Failback vs. Fail Back"
dateModified: "2026-09-03"
---

# Backup vs. Back Up, Failover vs. Fail Over, Failback vs. Fail Back

**Backup** is a noun spelled as a single word, while **back up** is a verb spelled as 2 words. **Failover** is a noun spelled as a single word, while **fail over** is a verb spelled as 2 words. **Failback** is a noun spelled as a single word, while **fail back** is a verb spelled as 2 words.

::: tip

- The same applies to all words that can work as both nouns and verbs. For example, **roll back** and **rollback**, **log in** and **login**.
- You may encounter a situation where you need to describe an item that has been backed up. In this case, use the adjective **backed-up** spelled as a hyphenated compound word. 

:::

### Examples

1. Veeam Backup & Replication does not necessarily use [a backup]{.mdhl-correct} created by one job and [one backup repository]{.mdhl-correct} as a source of data. It can copy data from [backups]{.mdhl-correct} created by different jobs and even from different [backup repositories]{.mdhl-correct}. 
2. If you do not want [to back up]{.mdhl-correct} or replicate some files and folders on the VM guest OS, you can exclude them from [the backup]{.mdhl-correct} or replica.
3. [Failover]{.mdhl-correct} is a [process]{.mdhl-correct} of switching from the original VM on the source host to its VM replica on the target host.
4. If a VM becomes unavailable in case of a disaster, you [can fail over to]{.mdhl-correct} the VM replica and quickly restore services in the production environment.
5. If you want to resume operation of a production VM, you [can fail back to]{.mdhl-correct} it from a VM replica. When you [perform failback]{.mdhl-correct}, you get back from the VM replica to the original VM, shift your I/O and processes from the target host to the production host and return to the normal operation mode.
6. [If you fail back from]{.mdhl-correct} a VM replica to the VM in the original location, you can instruct Veeam Backup & Replication to [perform quick rollback]{.mdhl-correct}. 
7. [You can]{.mdhl-correct} power off running VM replicas on target hosts and [roll back to]{.mdhl-correct} the initial state of these replicas.
8. To upload [backed-up data]{.mdhl-correct} to Amazon EC2, Veeam Backup & Replication uses an auxiliary EC2 instance — a proxy appliance.
9. For every disk of [a backed-up machine]{.mdhl-correct}, Veeam Backup & Replication creates an empty EBS volume in Amazon EC2.