What are web hosting and domain name? What are the options available to a blogger?

When you open a blog or website, you need to keep it on some computer/ server where it is available all the time. When someone types your site or blog's address, it searches the world wide web (www) for that address, and if that address is found, your web browser shows your website or blog to him. This is how websites are made available to visitors/ searchers/ links.
So, it is very basic that your website or blog is 'hosted' somewhere on the www. There are big internet companies that do this job for you either free or on payment. Sure, you get better services when you pay.
From bloggers' point of view, web hosting is of great importance. If you open a free blog on Blogger (example.blogspot.com) or Wordpress (example.wordpress.com), that blogging platform does three things for you:
  • It gives you a domain name or web address (e.g. example.blogspot.com).
  • It hosts your blog on its own servers.
  • It gives you the facility to write content on the blog and make the blog beautiful.
Blogger, Wordpress and some other blogging platforms do it for free. They do so with some other business in mind, but as a blogger you need not bother as long as the blog comes free to you.
However, these platforms cannot keep providing you free services even when your website or blog grows very big. As you grow, you need more space, you also need a way to make money from the blog. For these, you need something more than the free platforms can provide you. You also do not want to be limited by their terms and conditions. This is the time, you look for web hosting services. These services are provided by companies with huge computers that are connected to the web and are properly maintained and secured all the time.
Web hosting has a price. That depends upon the type of hosting you buy: shared web hosting or exclusive hosting or... A large number of web hosting options are available in the market and you can choose a plan according to what facilities you want. You have to pay for hosting your blog - year after year.
Web hosting is a big business as millions of websites are to be made available all the time. That requires huge infrastructure in the form of servers, networks, web security systems and a series of software that cannot afford to shut down even for a second or go slow due to traffic.

web hosting and domain name

Let me repeat that web hosting is not enough for your blog or website's presence on the web. You need a domain name. When you are not on a free platform such as Blogger, you need to buy a domain name and renew it year after year. 
If you are new to blogging or are an established blogger but do not understand the technical details about how blogs and websites are hosted and maintained, subscribe to the blog so that you are updated from time to time.