When we talk about internet, web etc we always use and we are aware about 'search'. We will be searching for something. But the search ends only when we find what we searched. In other words we 'located' what we searched for. To locate something precisely it should have a proper and identification detail or address. We locate our searched resource by an identity or address that is expressed in a standardised uniformly identifiable format of that source. Such standardised naming convention is called Uniform Resource Locator or URL in short. URL is more commonly taken as web address.
What we see on top of this page top on the address bar - (http://www.indiastudychannel.com/experts/43448-the-meaning-of-URL-and-uses-of-it.aspx) is a URL
The URL helps the browser to locate the resource.
Inthe above URL of this page http – stands for HyperText Transfer Protocol- one kind ofprotocol used for search( there are other protocols like FTP, TFTP etc also)
www stands for world wide web, which is more commonly known to us
the part 'indiastudychannel.com' is the domain name or the principal and main name of the web site .It is also known as IP address.
the part '/experts/43448-the-meaning-of-URL-and-uses-of-it' is called the directory or the specific location of the page on the server
aspx denotes the file extension or file type of the web page.
In a URL protocol, domain, directories, and files are all separated by forward slashes ( / ).
There are prescribed standard guidelines to denote a URL. Certain characters are not to be used in URL Only alphanumeric characters and a few more special characters only are to be used.
The answer given is in general terms made for easy understanding of a layman and may not be a technically perfect answer.
By the above it is clear what the use of a URL is
How to create a URL involves more technical knowledge and cannot be given in the general Q&A post. However, just to know that there are free services and paid services which give you domain names so that you can create your own web site or blog sites and content or resources.