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Linux Is Everywhere: A Tour of Real‑World Uses
Linux is not just “another operating system.” It quietly runs an enormous amount of the world’s technology. This chapter gives you a big‑picture tour of where Linux is used today, so you can see why learning it matters.
Desktops and Laptops
On personal computers, Linux is best known through complete systems called distributions (distros), such as Ubuntu, Fedora, and Linux Mint.
Typical desktop/laptop uses:
- Everyday computing
- Web browsing, email, office suites (e.g., LibreOffice), media playback
- Suitable as a daily driver for many users
- Development workstations
- Many programmers and DevOps engineers prefer Linux for:
- Programming languages (C, Python, Go, Rust, etc.)
- Tools like
git,gcc,make, containers, and virtual machines - Privacy‑ and customization‑focused systems
- Distros focused on privacy, anonymity, or heavy customization
On desktops, Linux is a visible choice among many. On servers and in devices, it is often the default.
Servers: The Backbone of the Internet
Linux dominates servers—the machines that run websites and online services.
Web and Application Servers
A huge share of the world’s websites and apps run on Linux:
- Web servers such as Apache and Nginx commonly run on Linux
- Application servers (for Java, Python, Node.js, Ruby, PHP, etc.) usually run on Linux
- Popular platforms and frameworks (Django, Rails, Spring, Express, Laravel) are typically deployed on Linux machines
If you visit a major website, stream music, use a social network, or log into an online game, it is very likely that Linux servers are involved.
Databases and Storage
Many database servers use Linux:
- Relational databases: MySQL, MariaDB, PostgreSQL, Oracle Database
- NoSQL and data systems: MongoDB, Redis, Cassandra, Elasticsearch
Linux is also a common base for:
- Network storage (NAS, SAN)
- Distributed file systems (e.g., Ceph, GlusterFS, HDFS)
- Backup servers and archival systems
Enterprise and Hosting
In data centers and corporate environments, Linux is widely used for:
- Virtualization hosts (running many virtual machines)
- Email, DNS, DHCP, directory services
- Internal business applications (intranet sites, ERP, CRM, etc.)
When companies “host” services—either in their own building or through a provider—Linux-based systems are often at the core.
Cloud Computing and Virtualization
Major cloud providers are built around Linux.
Public Cloud Platforms
On platforms like:
- Amazon Web Services (AWS)
- Microsoft Azure
- Google Cloud Platform (GCP)
most virtual machines and services are Linux-based. Even many “serverless” and managed services run on Linux behind the scenes.
Common uses:
- Running Linux virtual machines (VMs) to host apps and websites
- Using container platforms (e.g., Kubernetes) which run primarily on Linux
- Building elastic, scalable services that depend on Linux infrastructure
Containers and Orchestration
Modern DevOps and cloud-native applications revolve around:
- Containers (Docker, Podman, LXC/LXD)
- Orchestration systems (Kubernetes, OpenShift, Nomad)
These technologies rely heavily on Linux features (namespaces, cgroups, etc.), so most production container deployments use Linux as the host OS and often inside the containers as well.
Mobile Devices: Android and Beyond
Linux also powers a huge portion of smartphones and tablets.
Android
Android’s core uses the Linux kernel. While Android’s user interface and app environment are different from desktop Linux distributions, the underlying kernel is Linux.
This means:
- Most non‑Apple smartphones and many tablets are Linux-based
- Many smart TVs and set‑top boxes that run “Android TV” or similar variants also rely on Linux
Other Mobile and Niche Systems
Although less common:
- Some specialized or experimental phones run Linux-based mobile distros (e.g., postmarketOS, Ubuntu Touch)
- Certain handheld gaming devices and portable consoles use customized Linux systems
Embedded Systems and IoT (Internet of Things)
Linux is widely used in embedded systems—small computers built into other devices.
Examples:
- Home devices
- Routers and Wi‑Fi access points
- Smart TVs, streaming boxes, home assistants
- Network-attached storage (NAS) boxes
- Consumer electronics
- E‑book readers
- Cameras and DVRs
- Some smart appliances
- Industrial and commercial devices
- Factory controllers and automation systems
- Point‑of‑sale terminals and kiosks
- Digital signage and display systems
- Automotive
- In‑car entertainment and navigation systems
- Vehicle control and telemetry in some cases
In these contexts, Linux is usually customized and hidden from the end user—there may be no visible “desktop,” just the device’s interface.
Supercomputers and Scientific Computing
Linux is the standard for high‑performance computing (HPC):
- Almost all of the world’s top supercomputers run Linux or Linux-derived systems
- Used in climate modeling, physics simulations, genomics, AI research, and more
Typical setups:
- Large compute clusters of Linux servers
- Specialized, highly optimized Linux distributions for HPC workloads
Researchers and engineers rely on Linux for performance, scalability, and the ability to customize the system deeply.
Networking and Infrastructure Devices
Many network and infrastructure devices run Linux internally, even if you never see a “Linux logo.”
Examples:
- Enterprise routers, switches, and firewalls
- Load balancers and VPN gateways
- Telecom equipment (cell towers, core network components)
- Edge computing devices close to data sources (e.g., sensors, gateways)
Manufacturers often build specialized network operating systems on top of the Linux kernel.
Specialized and Professional Environments
Linux appears in many niche and professional domains:
- Media production
- Audio and video editing workstations
- Broadcast systems and playout servers
- Scientific instruments
- Lab equipment, data acquisition systems
- Security and forensics
- Security auditing distributions
- Forensic analysis tools running on Linux
- Education and training
- School computer labs
- University teaching and research environments
In many of these areas, Linux is chosen for flexibility, cost, or the ability to modify it for specific needs.
Everyday Services You Use (Likely Running on Linux)
To connect the dots, here are typical services that are often powered by Linux:
- Email services and webmail
- Social networks and messaging apps
- Streaming platforms (music, video)
- Online banking portals
- Cloud storage and file-sharing services
- Code hosting platforms and developer tools
You might never log into a Linux shell on these systems, but Linux is working in the background to make them possible.
Why This Matters for You
Understanding where Linux is used today helps you see:
- Relevance: Skills you learn are applicable across many fields—IT, development, data, networking, embedded, and more.
- Transferability: Once you’re comfortable with Linux on a desktop or in a virtual machine, that knowledge carries over to servers, cloud platforms, and many devices.
- Opportunity: Many technical roles (system administration, DevOps, backend development, security, cloud engineering, data engineering) assume basic Linux familiarity.
In the rest of this course, you’ll focus on the practical skills that let you work with Linux in these various environments—starting on your own machine, then extending out to servers, networks, and beyond.