> For the complete documentation index, see [llms.txt](https://olb.gitbook.io/linux-essentials-certification/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://olb.gitbook.io/linux-essentials-certification/1.linux_community/1.4-ict_skills.md).

# 1.4 ICT skills and knowledge

**Weight 2**\
Key knowledge areas

* Desktop skills
* Getting to the command line
* Industry uses of Linux, cloud computing and virtualization

Partial list of the used files, terms and utilities

* Using a browser, privacy concerns, configuration options, searching the web and saving content
* Terminal and console
* Password issues
* Privacy issues and tools
* Use of common open source applications in presentations and projects

***

## Linux interfaces

CLI or GUI

### Desktop env. / GUI - Graphical User Interface

* Linux user can choose their GUI
* **Gnome** : KISS - GTK (C language)
* **KDE** : lot of settings - Qt (C++)

### CLI - Command Line Interface

* Terminal (Gnome) or Konsole (KDE) - (emulate *Teletype* / tty)
* CTR+ALT+F# => tty console

## Presentation & project tools

* LibreOffice Impress (Powerpoint-like) - `.odp` format
* Beamer , LaTeX for presentation w/ code
* Reveal.js for HTML presentations
* GanttProject or ProjectLibre (MS Project)

## Industry use of Linux

* 68% website servers in the world are Unix / Linux

### IaaS

Infastrucure as a Service

* VMs managed over hypervisor
* hypervisor allows virtualization on a large host machine
* Xen , KVM, VirtualBox are Linux hypervisors
  * **KVM** (RedHat) most prominent
  * **VirtualBox** (oracle) used by end users
  * **OpenStack** collection of OSS for IaaS on premise

### PaaS

Platform as a Service Platform to deploy & run applications - **Heroku**

### SaaS

Software as a Service DropBox, SalesForce ...

## Privacy w/ Internet

### cookie tracking

* some cookies are used by Ad network (third parties) for tracking activities
* 3d party cookies alo used by social networks

### DNT

Do Not Track

* opt-out from tracking
* extra flag `DNT:1` sent in http header

### Private mode

delete cookies after session

### passwords

* use password manager
  * **KeePass** in the file system
  * **Bitwarden** in the cloud

## Encryption

### TLS

* successor of SSL
* v1.3 current version
* use mostly w. https

### GnuPG

* Gnu Privacy Guard (OSS version of OpenPGP)
* Encrypt / Decrypt text and emails
* encrypt your email with public key of your recipient / only private key of recipient can decrypt
* use your private key for signature

### Disk Encryption

* stacked encryption : on top of filesystem
  * *EncFS* (no need to be root)
  * *Veracrypt* (former *TrueCrypt*)
* block encryption : below the filesystem
  * *dm-crypt* native in Linux kernel (use with *LUKS* extension)