A web browser is an application for displaying web pages and embedded media.
There are many different browsers, but the most used besides the Internet Explorer is Mozilla Firefox. Firefox is developed by the Open Source community and available for free (Windows, Linux, MacOS). You will find it in almost every Internet-café. Most other browsers are similar.

The following text exemplarily explains the usage of Mozilla Firefox 

You can open Firefox by clicking the firefox-icon  (Xubuntu standard: inside the upper panel).
You will probably get a window according to this sheme (not all bars are always shown):

Title bar
Menu bar
Navigation bar
Bookmarks bar
Tab bar
Web page S c r o l l b a r
Scrollbar  
Find bar
Status bar

Title bar

The title bar shows the title of the actually loaded site. The buttons are the usual ones (see Windows).

Menu bar

When you click on one of the entries in the menu bar, a menu with commands is opened.
Example: click Bookmarks > Bookmark This Page. A dialog for saving a bookmark of the current page appears. Just click Done without making any changes to Name:, Folder: and Tags:. Click Bookmarks again. The new bookmark should appear at the bottom of the menu now.

The Menu Reference of the Firefox Help explains all menu entries.
You can always get to the Firefox Help by pressing F1 on the keyboard while Firefox is active.

The symbol at the right side of the menu bar is animated while a page is loading.

Navigation bar

The back button  opens the previously visited page.
The forward button  opens page that was shown before you went back.
The angle ∨ on the right side of the forward button opens a menu with the recent pages.
The refresh button  reloads the current page. Sometimes useful if a page is displayed in a strange way or has been updated.
The stop button  interrupts current page loading. Useful if loading a page takes too long and you want to go anywhere else.
The home button  always opens previously set homepage (for example email, news or another often used page).

The large bar inside the navigation bar is the address bar. It shows the Internet address (URL / URI) of the currently loaded page.
If you want to visit a web page, you can type the address of the page inside the address bar and press enter to get there. (Double click the current address to highlight it and it will be deleted when you start typing the new address.)
Usually it’s not necessary to type the whole address – you only have to type the domain name and the suffix (see Components of a URL at the bottom of this page). The URL will be completed after pressing enter. The leading www is also added automatically.
If you only type a keyword in the address bar and press enter, Firefox will search the web for matching pages (normally by using google).
A menu with bookmarked and previously visited pages is shown while you’re typing. Only pages matching the text you already typed are shown. You can select a page by clicking on it or by using the arrow keys ↓↑ on your keyboard.
Clicking the angle ∨ on the right side of the address bar opens a menu with the already entered addresses.

Example:
Go to the main page of the BBC by typing {font-family:courier,monospace}bbc.co.uk in the address bar.
Maybe you want to read some of the linked articles. You can just click one, read it and then go back  to the main page and select the next one.

The search box on the right side of the navigation bar gives quick access to different search engines).

Bookmarks bar

When you’re saving bookmarks (%{color:#037}**Bookmarks > Bookmark This Page**% or Strg + d), you can select the Folder were the bookmark is saved. Bookmarks saved inside the Folder: Bookmarks Toolbar appear in the bookmarks bar. Folders created inside the Folder: Bookmarks Toolbar also appear in the bookmarks bar. Clicking one of them opens a menu with the links saved inside this folder.

Tab bar

You can use tabbed browsing to open multiple pages inside one Firefox window at the same time. Opening several pages at one time makes surfing the Internet more effective, since you reduce the time waiting on a web page to load.
If you click on a link with the right mouse button, a context menu is opened. Select Open Link in New Tab to use tabbed browsing.
If your mouse has a middle button or a a scrolling wheel with click function, you can middle-click links – they will open in a new tab.

Web pages – links and forms

Web pages usually contain links to other web pages. Links can be text (normally underlined) or images. If you move the mouse pointer over them, the appearance of the mousepointer changes (usually to a hand symbol). If you click the link, the linked web page is loaded.
Web pages may also contain elements of a form – for example a field for text input and a button to submit. Be careful with giving away personal data in such forms.

Scrollbar

Scrollbars are shown if the content of a web page is bigger than the window. Usually you have a vertical scrollbar to scroll up and down. You will get a horizontal scrollbar if a web page is too wide to fit inside the window.

Find bar

With the find bar you can search the current website for text. You can get the find bar displayed by clicking Edit > Find in the menu bar or by pressing the keys Strg+f simultaneously.

Status bar

The status bar shows many different informations about the currently loading/loaded web page.
While loading a web page, the status bar shows what’s actually done.
When you’re moving the mousepointer over a link inside a web page, the link target is shown.
If you’re viewing a page that uses HTTPS, a lock symbol and informations about the authentication are shown on the right side.
…

Components of a URL

Example: {font-family:courier,monospace} en.wikipedia.org/wiki/URL

Bookmarks