By the end of this lesson you will be able to
- Explain what browsing history, cookies and the cache are and why each exists.
- Clear stored browsing data for a chosen time period and predict what changes.
- State clearly what private browsing hides and what it does not.
- Review and change a site's permissions, such as location, camera and notifications.
- Decide whether a browser extension is worth installing.
Your browser remembers a great deal so that the web feels convenient: which sites you visited, who you are logged in as and what pictures a page uses. Some of this memory helps you. Some of it lets companies follow you around the internet. Knowing what is stored, and where the controls are, lets you decide for yourself instead of guessing. This lesson also clears up a widespread myth: private browsing does not make you invisible.
What your browser remembers
Three different things are kept on your computer by the browser. They are easy to confuse, so keep them apart.
| What it is | What it is for | What happens if you clear it |
|---|---|---|
| Browsing history: a list of pages you have visited | Lets you find a page again and fills in suggestions as you type | The list disappears. Nothing else changes. |
| Cookies: small text files a website asks your browser to keep | Remember that you are logged in, your language, items in a basket | You are logged out of sites and preferences are forgotten. |
| Cache: saved copies of images and page parts | Makes pages you have visited before load faster | Pages load slower the first time, and old broken copies are removed. |
A cookie is a bit like a cloakroom ticket. When you hand your coat in, you get a numbered ticket. Next time, you show the ticket and they find your coat without asking who you are. A login cookie works the same way: the site gives your browser a token, and the browser shows it on each visit, so you stay logged in. If someone copies your ticket they can collect your coat, which is why a stolen login cookie is dangerous and why you should log out on shared computers.
Read this figure as text
A network diagram showing a browser storing history, cookies and cache, with a website sending cookies and page files.
A diagram with a laptop labelled Your browser on the left and a web server on the right. An arrow from the web server to the browser is labelled Page files, which are stored as the cache so the page loads faster next time. A second arrow from the web server to the browser is labelled Cookie, which is stored as a cookie so the site recognises you when you return. The browser also keeps its own list called History, which the website does not send; it is your own record of the pages you visited.
First-party and third-party cookies
A first-party cookie comes from the site you are visiting, for example to keep you logged in. A third-party cookie is set by a different company whose content is embedded in the page, such as an advert or a social media button. The same company can set cookies on many sites and so follow you from one to another. For this reason Firefox blocks many such trackers by default, and other browsers let you block third-party cookies in Settings.
Looking at and clearing your data
You can look at your history and clear any of these stores. Clearing is useful on a shared computer, when a site is behaving oddly (an old cached copy may be at fault), or just for tidiness. Before you clear, remember the effects: clearing cookies logs you out everywhere, and clearing the cache may make the next page loads slower.
Clear browsing data
Menus change slightly between versions. Ctrl+Shift+Delete opens the clear-data window in Firefox, Edge and Chrome.
Firefox on Ubuntu 24.04
Step 1: Look at your history
Press Ctrl+H to open the history sidebar. Click a page to open it. Press Ctrl+H again to close the sidebar.
You should see: A list of sites grouped by day appears.
Step 2: Open the clear window
Press Ctrl+Shift+Delete.
You should see: A window called Clear Recent History appears.
Step 3: Choose time and items
Set Time range to clear to Last hour. Open the details and tick Browsing & download history. Leave Cookies unticked for this practice. Click OK.
You should see: The last hour disappears from the history list, but you are still logged in to your sites.
Step 4: Find cookie settings
Open the menu, choose Settings, then Privacy & Security. Look at Enhanced Tracking Protection and the Cookies and Site Data section.
You should see: You see the tracking protection level and a Clear Data button.
Microsoft Edge on Windows 11
Step 1: Look at your history
Press Ctrl+H.
You should see: A history panel appears, grouped by day.
Step 2: Open the clear window
Press Ctrl+Shift+Delete.
You should see: A window called Delete browsing data appears.
Step 3: Choose time and items
Set Time range to Last hour. Tick Browsing history only. Untick Cookies and other site data for this practice. Click Delete now.
You should see: The last hour disappears from history, but you stay logged in on your sites.
Step 4: Find cookie settings
Open Settings from the three-dot menu, then Cookies and site permissions, and look at Manage and delete cookies and site data.
You should see: You see switches for allowing and blocking cookies.
Private browsing: what it does and does not do
Private browsing is called a private window in Firefox, InPrivate in Edge and Incognito in Chrome. Open it with Ctrl+Shift+P in Firefox and Ctrl+Shift+N in Edge and Chrome. When you close the private window, the browser throws away the history, cookies and form entries from that session. That is all. It is useful for logging in to your email on a friend's computer, for shopping for a surprise gift, or for testing whether a site works without your logins.
- Does not keep history here
- Deletes cookies when closed
- Forgets form entries
- Starts without your logins
- Hide you from the websites
- Hide you from your internet provider
- Hide you from a school or employer network
- Protect you from malware or fake sites
- Remove downloads and bookmarks
Read this figure as text
Two columns showing what private browsing removes from the computer and who can still see your activity.
Two columns. Left, titled Private browsing does: it does not save history on this computer; it removes cookies and site data when the window closes; it does not remember form entries; it starts without your logins. Right, titled Private browsing does not: it does not hide you from the websites you visit; it does not hide your activity from your internet provider; it does not hide it from a school, employer or Wi-Fi owner who runs the network; it does not protect you from viruses or fake sites; it does not stop downloaded files or bookmarks from staying on the computer.
Site permissions
A website can ask your browser for special access: your location, your camera, your microphone or permission to send notifications. Each is a site permission. A map site needs your location, and a video call site needs your camera and microphone, so granting those is reasonable. But a recipe site asking to track your location or a random site asking to send notifications is not. The browser always asks first. Read the question, and choose Block or Not now unless you can say why the site needs it.
You can review the permissions given to one site at any time. Click the small icon at the left of the address bar (a padlock or settings symbol), then look for Connection secure, Permissions or Cookies and site data. Here you can reset or remove access. For all sites, look in Settings, under Privacy (and Site permissions in Edge or Chrome, or Permissions in Firefox's Privacy & Security page).
Extensions: useful, but choose carefully
A browser extension is a small add-on program that changes what the browser does, for example by blocking adverts or checking spelling. Because an extension runs inside your browser, a bad one can see the pages you visit, including what you type. Install very few. Use only the official stores: Firefox Add-ons for Firefox, Edge Add-ons for Edge and the Chrome Web Store for Chrome. Never install one because a pop-up or a stranger told you to.
| Question | Why it matters |
|---|---|
| Do I really need it? | Each extension adds risk, and most people need very few. |
| Who made it, and is the page from the official store? | Look for a known publisher and a store listing, not a link from an email or advert. |
| How many users and what do the reviews say? | Many users and steady, detailed reviews are a good sign. A brand-new add-on with few users deserves caution. |
| What permissions does it ask for? | Read and change all your data on all websites is a very strong permission. A simple tool should not need it. |
www.example.com wants to know your location
This is an educational simulation.
- Marker 1: Click the icon here to review permissions
- Marker 2: Read who is asking and for what
- Marker 3: Block: safe choice for a recipe site
- Marker 4: Allow: only if the site truly needs it
Read this figure as text
A simulated browser window with a site asking to know your location and to send notifications, with Block and Allow buttons.
A simulated browser window showing a recipe site at https://www.example.com/recipes. A permission box over the page says: www.example.com wants to know your location, with the buttons Block and Allow. Marker 1 points to the address bar and site information icon, where you can review permissions later. Marker 2 points to the question text, which names the site and the permission. Marker 3 points to the Block button, the safer choice for a recipe site. Marker 4 points to the Allow button, appropriate only if the site really needs it. This is an educational simulation.
Common mistakes
✖ Instead of: Believing private browsing makes you anonymous.
✔ Do this: It only stops your own browser keeping a record. Websites and networks can still see what you do.
✖ Instead of: Clearing everything because the computer feels slow.
✔ Do this: Clearing history does not speed anything up. Clear only the items you need, and understand the side effects.
✖ Instead of: Clicking Allow on every permission pop-up to make it go away.
✔ Do this: Block or choose Not now unless you can say why the site needs it.
✖ Instead of: Installing several extensions from a pop-up or an advert.
✔ Do this: Use only official stores, install few extensions and remove ones you do not use.
If something goes wrong
- A site says my login has expired or keeps logging me out.
- Cookies may be blocked or have been cleared. Check that cookies are allowed for that site in the site information panel, and avoid clearing cookies on exit unless you want that.
- A page shows old content or looks broken after a site update.
- Press Ctrl+Shift+R for a hard reload. If it persists, clear the cache for the last day from the Clear data window.
- I keep getting pop-up notifications from a site.
- Open Settings, find Notifications under Privacy and Security (Firefox) or Site permissions (Edge and Chrome), and remove or block that site.
- I accidentally blocked a site that needs my camera or location.
- Click the icon at the left of the address bar, find Permissions, and change the setting back to Allow or Ask. Reload the page.
Key terms
- browsing history
- Browsing history is the list of pages your browser remembers that you have visited.
- Cookie
- A small file a website saves in your browser to remember things about you.
- Cache
- A small store of recently used data kept close by so it can be fetched again quickly.
- private browsing
- Private browsing is a window that does not save history or cookies on your device once you close it.
- site permission
- A site permission is a setting that decides whether one website may use your location, camera, microphone or notifications.
- third-party cookie
- A third-party cookie is a cookie set by a different site from the one you are looking at, often by an advertiser.
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.
Review what your browser keeps
Open your browser's history and find a page you visited today. Clear only the last hour of browsing history, with cookies left unticked, and check that you are still logged in on a site where you have an account (do not type any password). Open a private window, visit example.com and close it again; check that the visit does not appear in your history. Finally, open Settings and find the notifications and location permission lists and note whether any site is allowed.
Challenge: audit your extensions
Open the extensions or add-ons page of your browser (the menu, then Extensions or Add-ons). For each extension installed, write down what it does, who made it and what permissions it has. Decide whether to keep or remove each one, and give a reason. If you have none, write three questions you would ask before installing one.
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
- History is a list of pages, cookies are small tokens from sites and the cache is saved page parts.
- Clearing cookies logs you out. Clear only what you need.
- Private browsing only stops your own browser keeping a record. Websites and networks can still see you.
- Allow permissions only when you can say why the site needs them.
- Install very few extensions, only from official stores, and read their permissions.
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.
- Firefox privacy and security help (Mozilla)
- Microsoft Edge help and learning (Microsoft)
- Google Chrome Help (Google)
- HTTP cookies (MDN Web Docs)