A domain name is the address of a website on the internet. The difference between real world addresses and website addresses is that in the real world, one place has only one address but on the internet, one website may have more than one address.
Let’s illustrate this with an example. 10 Downing Street, Westminister, London is well-known cause the English Prime Minister lives there. This address is unique. In the case of websites, it’s more complicated.
An example is www.radio-dodo.com and www.radiododo.com. Both addresses lead to the same Mauritian podcasting Website. Here, we have a redirection: www.radiododo.com is redirected to www.radio-dodo.com. We could have another version where there is no redirection but where each address points directly to the same server and you could access the website from each address without any change in the address bar.
Now, I will express my views on how to choose a domain name. I believe that, nowadays, people no more retain the domain name except for the well-known ones such as google, hotmail, yahoo and so on. What they do when they want to go on a website is they look for it on a search engine, select it from their bookmarks or from their social networking websites. Some people like me still retain some urls cause we find it easier when we are looking for a specific content but I believe that we are a minority; maybe it’s because we are web developers…
So, to make your website available to the majority using a search engine to find anything. You’d better lay some emphasis on the choice of your domain names. Do not hesitate to use keywords in the domain name separated by dashes. This will certainly help to have a better rank on search engines. The domain name should reflect the content of your website.
Give it a try on google for example, just type two keywords and look at the domain names of the results you get. Note that you need to have relevant contents on your website and you need to update frequently in order to be able to gain ranks on search engines.