The slide show in the panel below demonstrates a number of key points you should be aware of when using a browser.
If you are looking for more detail on a specific feature take a look at the entries on the Home page, or you can use the magnifying glass [near the top right corner of the screen] to "Open search bar" then search this site for specific information.
If you still don't have the full answer to your question then do a Google Search to find further information on your topic.
The figure in the white oblong box above shows the number of slides available for viewing.
Click the < or > icons to move backwards and forwards through the slides.
If you are not familiar with the workings of 'windows' and 'tabs' in a browser then click here to read a document [produced by HowToGeek, that covers features common to popular browsers] which clearly explains the differences.
A useful analogy would be that a 'window' is a running instance of a browser that you can think of as being a book. Then within the book you have one or more 'tabs' open, each of which points to a specific page located at different web sites.
You can easily move between different 'windows' and 'tabs' just by clicking on them.