Names, we all have one, well, except for the late Prince, who once went by a symbol, and even still, he went by the Artist Formerly Known as Prince. Point is, we all need names, descriptors, and titles.
Websites are no different. Every website requires a title, so much so, it has it's own element tag, <title>.
So, what is so important about the <title> element?
For one thing, it helps designates your website from the countless billions of other websites out there. Even if you decided to name your website something mundane like, <title>John Smith</title>, you inevitably narrowed down the search parameters greatly, making it even easier to find your site.
With that, you have found one of the primary aspects of web design and development, search engine optimization, or SEO for short. We're not going to go full on into SEO here, that's for another day, preferably a day where I have nothing going on and I am really, really, really bored. Just know that SEO is very important if you need your website to be viewed.
Other reasons for a <title> tag...say if someone loves your site and wants to bookmark it. By having a <title> tag in place, you have saved that person the effort to having to enter the name of your website manually.
Also, I'm not sure you've heard of this miracle technology, but some browsers come with a tabbing feature, where you can have multiple websites open at the same time...or as ADHD sufferers call it...The Hundred Tab Curse. Having tabs is great, even greater, being able to know which tab corresponds to which website...which is why a <title> tag is beneficial, as it has the ability to put the name of your website or whatever you decided to put there as your title, onto the relating tab.
One last bit on the <title> tag...when creating your <title>, you want to keep it unique, descriptive, but also short.
You want your site to stand away from the crowd, so that when someone needs to perform a Google search, or a Bing search....hahahahahah, no, no one uses Bing, that's just silly...anyway, you want them to be able to find your site quickly and have it be the top of the search results. Cause, you know, who really ever scrolls on search results, let alone goes to the second page?
You want your <title> to be descriptive, again, to make those search spiders work for you, and not the other way around.
Lastly, you want it short, cause I've seen titles that you could swear were written by Tolstoy, leaving me in the fun position of deleting all of they wrote and write in my own title if I decided to bookmark it.
Okay, speaking of keeping it short, this is becoming a bible, until next time kids.