In the client facing environment , I have got used of requests like that from clients.These situations require considerable amount of time to think and before saying something,precaution should be taken to avoid any technical pitfalls. Any technical word and client will lose the interest in the topic.
I have written one article where URL is explained and that will get you acquainted with regular terminologies.
The basic explanation can be, after site development, site is hosted on a server and mapped to a domain name. Just enter the domain name/ url on the address bar of your browser and site will start appearing. Simple? Understood?
if answer is yes then you bumped into a wrong category,please try our ‘technical’ series or ‘How to’ series. In ‘Imagine’ category, We are very much dedicated to our users who have their answer as ‘No’ and serve them a more simpler solution.
When website development is over, we have to host it on a server so what’s this hosting? I have a scenario which is very much similar to our situation, When we visit a restaurant for a buffet lunch/dinner then we behave like a client and restaurant owner is our host.
In our website hosting situation, ‘buffet’ is similar to our website which is available on our hosting server,’restaurant’. It is served to the client like us when we visit the restaurant like, as a user, when we punch the website URL/domain name on the browser, the site is available. This URL is restaurant name which we have visited. 
I am writing from quite some time about applying creativity and imagination to explain something technical to a non-technical people especially clients and i find it really difficult to satisfy all the sections of readers/listeners. But If i can really get minimum 1% of satisfied reader, then it would surely motivate.
