By the end of this lesson you will be able to
- Explain the difference between an application and the operating system.
- Describe what happens when software is installed, and why installing needs permission.
- Install an application from the official store of Ubuntu or Windows.
- Update an application and remove one properly instead of just deleting its icon.
- Choose the safest place to get an application from.
A laptop is only as useful as the programs on it. Sooner or later you will want to add one: a video player, a drawing tool, a language app. Doing this carelessly is one of the most common ways people end up with slow computers and unwanted extras. This lesson explains what installing really does, shows the safe route on Ubuntu and on Windows, and teaches you to remove software cleanly when you no longer need it.
Applications and the operating system
An Application (also called an app or a program) is software that helps you do a job: write a letter, browse the web, play music. The operating system is the layer underneath that manages the hardware and lets applications run. You do not install an operating system as you install an app, and applications cannot work without it.
Think of a kitchen. The building, the water and the electricity are the operating system. The blender, the kettle and the toaster are the applications. Each appliance is made for a particular kind of kitchen. A blender with the wrong plug does not work, and in the same way an application made for Windows does not run on Ubuntu unless something extra helps it.
What you install and remove
Read this figure as text
A stack with applications at the top, the operating system in the middle and hardware at the bottom.
Three layers from top to bottom. The top layer is applications, such as a browser, a word processor and a music player; these are what you install and remove. The middle layer is the operating system, either Ubuntu or Windows, which shares the hardware between applications and provides services they need. The bottom layer is hardware: the processor, memory, storage, screen and keyboard. An application talks to the operating system, never directly to the hardware.
What installing really does
An application is not one file. It is a collection: the program itself, pictures, settings, helper files and a shortcut. Installing means putting all of those pieces in the right places, telling the operating system that the app exists, and adding it to your list of apps. An Installer is a small program or package that does this work for you.
Installing changes the whole computer, not just your own folder. That is why the system asks for permission first. On Windows a box asks “Do you want to allow this app to make changes to your device?”. On Ubuntu a window asks for your password. These checks are a safety feature: a program that could install itself without asking could be used by criminals. Only approve a request that you started yourself, for software you chose.
- ChooseTrusted source
- InstallPermission asked
- UseSave your work
- UpdateFixes and patches
- RemoveUninstall properly
Read this figure as text
A cycle showing an application being chosen, installed, used, updated and finally removed.
A cycle of five stages. First, choose an application from a trusted source. Second, install it, which asks for permission. Third, use it. Fourth, update it from time to time, because updates fix faults and security holes. Fifth, when you no longer need it, uninstall it properly so that its files are removed. A new need then starts the cycle again.
Where applications come from
There are three usual routes. The best is the official store that comes with your system: the App Center on Ubuntu and the Microsoft Store on Windows. An app store is a catalogue run by the system maker. It lists apps, installs them with one click, keeps them updated and removes them cleanly. The second route is the maker's own website, where you download an installer. The third is a command-line package tool: apt on Ubuntu and winget on Windows. These tools do the same job as the stores, but by typed command. winget is Microsoft's tool, and apt is Ubuntu's. You will meet them properly in later modules, so here it is enough to know that they exist.
- Checked by the system maker
- One-click install
- Updates are managed
- Clean removal
Try this first.
- Often the newest version
- You run the installer yourself
- You must keep it updated
- Fake copies exist
Use with care.
- Fake installers are common
- Unwanted extras bundled
- No checking
- Hard to remove
Avoid.
Read this figure as text
A comparison of the official store, the maker's website and unknown download sites.
Three columns. Official store (App Center or Microsoft Store): checked by the system maker, one-click install, automatic updates, clean removal; the best first choice. Maker's own website: fine when you have the real address, but you install and update by hand, and you must check that the site is genuine. Unknown download sites and links in messages: often carry fake installers and unwanted extras; avoid them.
Installing from the official store
Install, update and remove an app
Menu names differ slightly between releases. Look for the same ideas: search, install, installed list, uninstall.
On Ubuntu (App Center)
Step 1: Open the App Center
Press the Super key, type
App Centerand press Enter. On older releases it is called Ubuntu Software.You should see: A window with a search box and featured apps opens.
Step 2: Search for an app
Click the search box and type the name or the job, for example
text editor. Click a result to open its page.You should see: The page shows the name, the publisher, a description, the size and an Install button.
Step 3: Install it
Click Install. When a window asks for your password, type your own Ubuntu login password, because you started this task.
You should see: A progress indicator runs, then the button changes to Open.
Step 4: Find it afterwards
Press Super and type its name. To update, open the App Center and look for Updates. To remove, open the Installed list, choose the app and click Uninstall.
You should see: The app is listed in Show Apps after installing and disappears from it after uninstalling.
On Windows 11 (Microsoft Store and Settings)
Step 1: Open the Microsoft Store
Click Start, type
Microsoft Storeand press Enter.You should see: The Store opens with a search box at the top.
Step 2: Search and read
Search for the app. Open its page and read the publisher name, the description and the ratings.
You should see: You see an Install or Get button, and the name of the company that made it.
Step 3: Install it
Click Install (or Get). Many Store apps install without further prompts. If the Windows prompt asks whether to allow changes, read the app name first.
You should see: The button changes to Open when the installation finishes.
Step 4: Update and remove
In the Store, open Library (or Downloads) and choose to get updates. To remove an app, open Settings, choose Apps, then Installed apps, click the three dots beside the app and choose Uninstall.
You should see: The app vanishes from the Installed apps list after you confirm.
Keeping apps up to date
Apps need updates for the same reason the operating system does: faults and security holes are found over time. Store apps update through the store, often by themselves. Apps installed from Ubuntu's package sources update with the system updates you met earlier. Apps that you installed from a website usually have their own update check, or you must install a newer version yourself. If you use many such apps, that is one more reason to prefer the store.
Removing an app properly
To Uninstall an app means to ask the system to remove its program, its helper files and its entry in your list of apps. Deleting an app's desktop icon or dragging a shortcut to the Trash does not do this. It only removes the shortcut, and the program itself stays on your storage, using space and sometimes still being updated.
- Program stays installed
- Storage space not freed
- May still need updates
Not a real removal.
- Program and helper files removed
- Space freed
- Leaves the app list
The right way.
Read this figure as text
A comparison of deleting a shortcut icon, which leaves the program, and uninstalling, which removes it.
Two columns. Delete the icon: only the shortcut disappears; the program and its files stay on the laptop, still using storage space, and it may still be updated; not recommended as a way to remove an app. Uninstall through the App Center, Settings or the Store: the program and its helper files are removed, space is freed, and the app leaves your list of apps; the right way.
Common mistakes
✖ Instead of: Approving every permission request to get rid of it.
✔ Do this: Read what it is for and approve only what you started yourself.
✖ Instead of: Installing three programs that do the same job "to see which is best".
✔ Do this: Pick one well-known app. Extras take space and need updates, and you rarely remove them afterwards.
✖ Instead of: Removing an app by deleting its icon.
✔ Do this: Use Uninstall in the App Center, or Settings, Apps, Installed apps on Windows.
✖ Instead of: Uninstalling apps with unfamiliar names to clean up.
✔ Do this: Some are parts of the system. Look the name up on the maker's official site first, or leave it.
If something goes wrong
- The installation fails or seems to freeze.
- Check your internet connection and the free space on the drive. Wait a few minutes, close the store and try again. If an update is running, wait for it to finish.
- The app is not in my list after installing it.
- Press Super (Ubuntu) or open Start (Windows) and type its name. Look in the Installed list of the store. A few apps need a restart before they show.
- Uninstall is greyed out or asks for an administrator.
- Only an administrator can remove some apps. Ask the person who looks after the computer. Some pre-installed parts of the system cannot be removed.
- I installed an app and the laptop now runs slowly.
- Open the installed apps list and find what you added recently. Uninstall it. If it was not from a trusted source, run a security scan, as a later module explains.
Key terms
- Application
- A program that lets you do a particular job, such as writing, browsing or editing photos.
- Installer
- A small program or package whose job is to put an application's files in the right places and register it with the computer.
- App store
- A catalogue run by the system maker where you find, install, update and remove apps in one place.
- Uninstall
- To ask the system to remove an application's program and files properly, not just its shortcut.
- winget
- Microsoft's typed-command tool for finding, installing and updating apps on Windows.
- apt
- Ubuntu's typed-command tool for installing, updating and removing software from its official sources.
Practise it for real
Reading is not the same as being able to do it. Complete these on your own computer, then tick only what you have actually done. These ticks are your own honest record: nothing checks them for you.
Install and remove one small app
Open the App Center (Ubuntu) or the Microsoft Store (Windows). Search for a small, well-known app that you do not yet have. Before installing, write down its name, its publisher and its size. Install it, open it once, then close it. Next, find it in the list of installed apps and uninstall it. Check that it no longer appears when you search for it from the Super key or Start.
Challenge: audit the apps on your laptop
Open your installed apps list (the App Center's Installed view or Settings, Apps, Installed apps). Make a table of ten apps with three columns: the app's name, what it does in your own words, and whether you use it. Do not uninstall anything yet. Mark the ones that you cannot explain, and look each of them up on the maker's official site or in the store before deciding anything. Write down which one app you would remove first and why.
Knowledge check
6 questions. You need 80% to pass. Mistakes here are part of learning, and you can retry as often as you like.
Summary
- Applications sit on top of the operating system, which manages the hardware.
- Installing puts files in place and registers the app; it asks permission because it changes the whole computer.
- The official store is the safest source: App Center on Ubuntu, Microsoft Store on Windows.
- Updates fix faults and security holes; stores help to keep apps updated.
- Uninstall through the store or Settings; deleting an icon is not removal.
Checklist: can you do these?
Marking a lesson as read does not prove you can do it. Skills count as demonstrated when you pass the quiz (not yet) and complete the practical tasks (not yet).
Related lessons
References and further reading
Official sources for details that can change between versions.
- Ubuntu Desktop Guide: Install more software (Ubuntu)
- Install apps from the Microsoft Store (Microsoft)
- Windows Package Manager (winget) documentation (Microsoft)