Editing Live CD (section)

== Uses ==
[[File:Trisquel 11 Live CD.png|thumb|230x230px|Live CD of [[Trisquel]] 11.0]]
Live CDs are made for many different uses. Some are designed to demonstrate or "test drive" a particular operating system (usually Linux or another [[Free software|free]] or [[Open-source license|open source]] operating system). Software can be tested, or run for a particular single use, without interfering with system setup. Data on a system which is not functioning normally due to operating system and software issues can be made available; for example, data can be recovered from a machine with an active virus infection without the virus process being active and causing more damage, and the virus can be removed with its defences against removal bypassed.

Although some live CDs can load into memory to free the optical drive for other uses, loading the data from a CD-ROM is still slower than a typical hard drive boot, so this is rarely the default with large live CD images, but for smaller live CD images loading the filesystem directly into RAM can provide a significant performance boost, as RAM is much faster than a hard drive, and uses less power.<ref name="Brickner000">{{cite book | title = Test Driving Linux: From Windows to Linux in 60 Seconds | first = David | last = Brickner | publisher = O'Reilly | year = 2005 | isbn = 0-596-00754-X | url-access = registration | url = https://archive.org/details/testdrivinglinux0000bric }}</ref> Experienced users of the operating system may also use a live CD to determine whether and to what extent a particular operating system or version is compatible with a particular hardware configuration and certain peripherals, or as a way to know beforehand which computer or peripheral will work before buying.<ref name="Brickner000" /> A live CD can be used to troubleshoot hardware, especially when a hard drive fails, and more generally as a [[recovery disc]] in case of problems. Some live CDs can save user-created files in a Windows partition, a USB drive, a network drive, or other accessible media. Live backup CDs can create an image of drives, and back up files, without problems due to open files and inconsistent sets.

A few additional uses include:
* installing a [[Linux distribution]] to a hard drive
* [[computer forensics]]
* Virus scanning and Malware removal<ref>{{cite web|url=https://www.howtogeek.com/howto/14434/scan-a-windows-pc-for-viruses-from-a-ubuntu-live-cd/|title=Scan a Windows PC for Viruses from a Ubuntu Live CD|website=howtogeek.com|access-date=19 March 2018|archive-date=19 March 2018|archive-url=https://web.archive.org/web/20180319214130/https://www.howtogeek.com/howto/14434/scan-a-windows-pc-for-viruses-from-a-ubuntu-live-cd/|url-status=live}}</ref>
* system repair and [[Data recovery|restoration]]
* testing new versions of software
* listing & testing hardware<ref>{{cite web|url=http://hdt-project.org/|title=Home - HDT Project|website=HDT Project|access-date=19 March 2018|archive-url=https://web.archive.org/web/20180725214325/http://www.hdt-project.org/|archive-date=25 July 2018|url-status=dead}}</ref>
* [[Internet kiosk]]s and public computers, which can be brought back to their original state by a reboot
* high security/non-invasive environment for a guest
* cracking, stealing, and changing passwords
* network security testing
* being the primary or backup operating system for any computer
* quick and simple clustering of computers<ref>{{cite web|url=http://www.flashmobcomputing.org/|title=FlashMob Computing – FlashMob Computing|website=flashmobcomputing.org|access-date=19 March 2018|archive-date=9 May 2008|archive-url=https://web.archive.org/web/20080509120957/http://www.flashmobcomputing.org/|url-status=live}}</ref>
* playing video games or running applications that require a different operating system
* providing a secure server platform where crucial files cannot be permanently altered
* providing a secure, reliable platform for the performance of high-vulnerability tasks such as [[internet banking]];
* Bypassing [[parental controls]] and other restrictions

Several live CDs are dedicated to specific type of applications according to the requirements of thematic user communities. These CDs are tailored to the needs of the applications in subject including general knowledge, tutorial, specifications and trial data too.

Some of these topics covers sub topics, e.g. IT administration breaks down to firewall, rescue, security, etc. type of live CDs. In some cases a particular Live DVD covers more than one topic.

=== Software appliances ===
[[File:Fedora 38 live CD.png|thumb|Live CD of [[Fedora (operating system)|Fedora]] 38]]
Packaging a [[software appliance]] as an installable live CD, or live ISO, can often be beneficial as a single image can run on both real hardware and on most types of virtual machines.

This allows developers to avoid the complexities involved in supporting multiple incompatible [[virtual machine]] images formats and
focus on the lowest common denominator instead.

Typically after booting the machine from the live CD, the appliance either runs in non-persistent demo mode or installs itself, at the user's request, to an available storage device.

=== Mounting without burning ===
[[File:Vbox160debian.jpg|thumb|Virtual [[OpenBSD]] machine configuration in [[VirtualBox]] with live image file (''6.3-Release-i386-bootonly.iso'')]]

The files on a live CD [[ISO image]] can be accessed in [[Microsoft Windows]] with a [[disk image emulator]] such as [[Daemon Tools]], or in [[Unix]] variants by mounting a [[loop device]]. Later versions of Windows (i.e. Windows 8 and later), and software available for earlier versions, allow an ISO to be mounted as a volume.

After mounting the live CD's filesystem, software on the live CD can be run directly, without booting it, by [[chroot]]ing into the mounted filesystem.

A live CD ISO image can also be mounted by [[Virtual Machine]] software such as [[VirtualBox]] and [[VMware Workstation]] or can be converted to a [[Live USB]] using [[SYSLINUX]]. [[List of tools to create Live USB systems|Special tools]] can automate this process.<ref>{{cite web | url = https://help.ubuntu.com/community/USB%20Installation%20Media | title = USB Installation Media - UNetbootin | website = community.ubuntu.com | publisher = Ubuntu Community | access-date = 11 February 2014 | archive-date = 22 February 2014 | archive-url = https://web.archive.org/web/20140222030330/https://help.ubuntu.com/community/USB%20Installation%20Media | url-status = live }}</ref>