All websites have an address, which you can see in the address bar of the browser.
The address above is a Google web search on - appropriately enough - web domains. The address starts 'google.com' and then there's a slash followed by gibberish (it's not gibberish to Google though); Before the slash - google.com - is the main page of the site. After the slash, the gibberish represents a unique web page.
A web address can contain more than one slash. Slashes represent sections of the main site. Look at this page
The main site is library.etbi.ie. After the slash is "sources2/domains". "domains" is the page and "sources2" is the section. Some websites - like this one - try to have meaningful web pages addresses, but others do not. The address below is from Princeton University library, we can see that from "libguides.princeton.edu" , but after that that we have no idea what the page is about (its actually about evaluating information sources, but you'd have to visit that page to find that out).
So what does this all mean? Basically, sometimes you can learn a lot from a web address and the first thing you should look at when evaluating a website is its address.
The end section of the main site - the com in google.com, the ie. in library.etbi.ie is the site's Top Level Domain (TLD). A TLD (from hereon, a domain) is an identifier that gives some insight into the type of website that you are visiting. Some domains have more authority that others. Seven domains were created in the early days of the Internet:
Originally intended for use by for-profit business entities e.g. www.amazon.com
Originally intended for use by non-profit organisations e.g https://www.oxfamireland.org/
Originally intended for use by organisations involved in networking technologies, such as Internet service providers and other infrastructure companies e.g. https://www.speedtest.net/
Originally intended for use by international organisations ratified by treaties involving two or more countries, e.g https://www.nato.int/
Limited to United States federal, state, country and local government bodies e.g. https://www.whitehouse.gov/
Limited to use by the United States military e.g. https://www.army.mil/
Almost entirely used by US universities and colleges e.g https://www.harvard.edu/
Some domains have more credibility than others.
Use of the two domains .gov, and .mil is restricted to the US government, so the very least, you know who is responsible for any sites ending in .gov or .mil and can trust the information on those sites (if you trust the US government, obviously).
.int is considered to have the strictest application policies of all top level domains, as its use implies that the site is an international organisation. If you apply for an .int domain, you will have to prove that you are a treaty-based international organisation (you're not a treaty-based international organisation are you?).
These days, anyone can register an .org, .com or .net website and there are no rules for content. While legitimate nonprofit & non-government organisations do use .org for their websites, many scammers and hoaxers like to use these domains because .org sounds more credible than .com (for example, elsewhere on this site, reference is made to martinlutherking.org)
The edu domain is mostly used by American universities and colleges, some of which are the among the best in the world. On the other hand, there are institutions like Bob Jones University, a private university known for its conservative cultural and religious positions, whose website also ends in .edu. Hence while you can trust .int, .gov and .mil domains, you should find out a little bit more about an educational institution that uses an .edu domain before you trust it.
These were the first seven domains. Since then many more have been added. Here's a complete list of top level domains as of January 2020. You may wish to reflect on the type of website that chooses to use the likes of .casino, .party or .sexy and how much you'd trust the information on that website.
Do domains actually matter? Yes! The White House is the official residence of the US President. Have a look at the following sites and decide which of these is the official White House site
See what a difference the domain makes?
Another reason for looking at web addresses is to avoid being the victim of a phishing attack. Phishing is the use of electronic communication - email mostly - to fraudulently attempt to gain personal or financial information by pretending to be someone trustworthy, like your bank or credit card company. You'll be asked to enter sensitive information into a form on a fake website that looks like the website you trust. One of the ways you can spot a phishing attack is to look at the address of the web site to which you're being sent. If you use PayPal, you'll know its address is https://www.paypal.com/ie/home. A phishing attempt might ask you to click on http://www.paypal-secure.online/, which is not the PayPal site.
Are you on Facebook? Do you know its web address? It's facebook.com
Facebook's web address is facebook.com. If you logged into facebook.net,(which doesn't exist any longer) phishers will gain access to your account and your details can now be sold to the highest bidder or be used to snare your Facebook buddies. Again, the domain (.net, not .com) makes all the difference.