Web Browsers, Cookies, Add-ons and Plug-ins

Hello students, welcome to Kwickprep. You close a shopping website, open it next day, and your cart is still full. How did the website remember you? The answer is a cookie. Today we will learn what a browser does, common browsers and settings, session and persistent cookies, and add-ons and plug-ins with their risks.

A web browser is application software that lets you open and view web pages. When you type a URL, the browser sends a request to the web server using HTTP or HTTPS. It then reads the HTML, CSS and scripts it receives, and turns them into the page you see. This is called rendering. Remember, a browser is not a search engine, because Google Search is a website that you open inside a browser.

Every browser gives you some common tools. The address bar is where you type a URL, or words to search. Tabs let you keep many pages open inside one window. Bookmarks, also called favourites, save a page so you can open it again with one click. History is the list of pages you visited earlier, and you can clear it.

There are many browsers, and all of them do the same basic job. Google Chrome, made by Google, is the most used browser in India and the world. Microsoft Edge comes built into Windows computers. Mozilla Firefox is open source, which means anyone can read its code, and it is run by a non-profit. Safari is made by Apple, for iPhones and Mac computers.

Browsers also have settings you should know. You can choose the home page, and the default search engine used from the address bar. You can clear your history, cache and cookies, where cache means saved copies of pages that load faster. A private window, called incognito in Chrome, does not save your history on that device. You can also block pop-ups, and decide which sites may use your camera, microphone or location.

Many students think incognito mode hides everything, but that is a myth. It only stops the browser from saving history and cookies after you close the window. The school or office network can still see which sites you visit. Your Internet service provider can still see them too. And if you log in to a website, that website still knows exactly who you are.

Now, the cookie. A cookie is a small text file that a website stores in your browser. On your next visit, the browser sends the cookie back to that website. This is how a site remembers your login, your shopping cart, your language and other choices. But cookies can also be used to track which pages you visit, so advertisers can show you targeted ads.

There are two main types of cookies. A session cookie is kept only in memory, while a persistent cookie is saved on the disk. A session cookie is deleted when you close the browser, but a persistent cookie stays until its expiry date, or until you delete it. So only a persistent cookie has an expiry date. A session cookie keeps your cart during one visit, while a persistent cookie powers the remember me option on a login page.

Cookies are also named by who sets them. A first-party cookie is set by the website you are actually visiting. A third-party cookie is set by some other company, such as an advertising network, whose content appears on that page. Third-party cookies can follow you across many websites to build a profile of your interests. That is why many sites show a cookie banner, where you can accept or reject them.

Next, add-ons. An add-on is a small program that adds a new feature to the browser itself. In Chrome and Edge, add-ons are usually called extensions. Examples are an ad blocker, a grammar checker or a dictionary that works on any page. They are installed from the browser's official store, like the Chrome Web Store or Firefox Add-ons.

A plug-in is slightly different, and exams test this difference. An add-on adds a feature to the browser, while a plug-in helps show a special type of content. An add-on changes how the browser works, but a plug-in runs content inside a page. A classic plug-in was Adobe Flash Player, for animations and games. Flash support ended in twenty twenty, and today browsers play videos and PDF files without separate plug-ins.

Add-ons and plug-ins are useful, but they also bring risks. A fake add-on may hide malware, which is software made to cause harm. An add-on with too many permissions can read everything you type, even passwords and OTPs. Some add-ons secretly show unwanted ads, or change your search engine. And too many add-ons slow down the browser. Pause and predict. A free coupon add-on asks to read all data on all websites. Should you install it? No.

Here are four habits that keep your browser safe. Install add-ons only from the official store, and check the reviews. Read the permissions list before you click add. Remove any add-on you no longer use. And keep the browser updated, because updates fix security holes.

Let us revise what we learned today. A browser requests web pages and renders them on screen. Common browsers are Chrome, Edge, Firefox and Safari, and incognito mode is not invisible. A cookie is a small text file that helps a website remember you. A session cookie is deleted when the browser closes, while a persistent cookie lasts until its expiry date. Add-ons add features, plug-ins show special content, and both must be installed carefully.