What is a website in IIS?

Question

I need to install a website locally for use only locally. I have Windows 7 and IIS version 7.5 installed and working. I get a page when I browse to localhost and I have a few pages linked to my home page.

I am confused about what a website is. For me, a website is whatever is at a domain. So in other words c-sharpcorner.com is a website.

But here is where I am confused. The software I am installing is a website and my understanding is that there can be multiple websites in an instance of IIS. That is confusing. Apparently I need to put the software in a directory somewhere and then create a virtual directory and a website. Something that is really unclear to me is how that relates to a specific URL.

I apologize for writing a vague question. It is difficult for me to write a specific question. I have searched C# Corenr for relevant articles and all I find is How to Create Virtual Directory of a Website. Thank you Anubhav Chaudhary for that but that is just a part of what I need. If someone knows of another relevant article then I will apreciate the help finding something. If someone wants to write a relevant article then I think it would be a useful topic.

One thing I can ask that is specific is, assuming I specify in IIS that my website is named testsite, how does that relate to what I put in the address bar of a browser? How do I browse to that website?