For most people, the internet is a somewhat foggy concept. A cloud of information that you surf on with your browser. Because World Wide Web was what made the internet popular and usable for ordinary people, many people think that the web as we use it, is the same as the internet, and because Microsoft did a few unsavoury things with their Internet Explorer back in the late 90's, there is still a lot of people who think that the internet is the blue e on their workspace.
Starting with the beginning, the internet is nothing but an insane amount of computers which have been connected. It all started as a military project during the Cold War where the American military got the (in hindsight) rather obvious idea that if you had a decentralized network of computers, you could prevent that all communication would stopped if the enemy hit the right computer. They got that part working in 1969. Back then it was called ARPANET, but it had the structure that has evolved into the internet.
This brings us to the next misunderstanding. The internet is not some cloud you surf on. That is a smart sales gimmick. Just like you pick up your phone and call a number and get a hold of someone, the internet is just a collection of numbers you call on your computer (IP addresses). Just like you wouldn't say something stupid like you were surfing the phone net when calling someone, the "surfing of the internet" is some terrible nonsense. You use your computer to make contact with another computer, which contains information and/or programs doing something you need, and that's it.
To navigate the internet and make calls these days, we use browsers like Internet Explorer, Firefox, Chrome, and whatever else they are called right now.
Staying with the telephone analogy, the choice between browser is like the choice between iPhone, Samsung Galaxy, Nokia etc. Which design and user interface do you like? Each browser has its advantages and disadvantages and you have to try them out, to see which one you prefer. There is no browser which can be said to be "the best". Some are more safe than others and some are faster than others, and who has the lead changes a bit with the upgrades of the various browsers.
As a developer of web pages, I generally recommend staying away from Internet Explorer, as it is generally the slowest of the major browsers, and there has been some issues with security. The latest versions are supposed to be pretty good, so if this is the browser you prefer, that's fine too.
If you make web sites it's easy, because then you need the five browsers that are used the most on your computer, and test all your sites/pages on all of them!
World Wide Web and other protocols
To navigate the internet today, and connect with other computers, we use the protocols which, in combination, make up the World Wide Web. These were invented by Tim Berners-Lee, while he was working at CERN. As to when it was invented, it is an ongoing discussion (depending on how you choose to focus on the various parts of the creation process), but in 1992/1993, World Wide Web was operational and accessible for the few people using the internet at the time.
There were other types of net, e.g. USENET and Fido-net, and other ways of finding informations on the net, e.g. the one named Archie. World Wide Web, which quickly became WWW, had some advantages compared to the other protocols, among other things, the graphical user interface and how easy it was to find your way around, and today this is the one we use when we are on the net.