I saw many times the situation when several domains are used for the same website. A common sense can be easily understood when for example different domains are used to demonstrate website pages are presented in several languages! But personally I don’t understand for which purposes the same website is made available under different domains in other cases? What advantages can be taken from displaying a website under different domains?

Getting trademark is difficult, so people operating a popular website generally find it easier to grab most of the important tld to protect their brand name and avoid any chance to let other people registering same domain name.

Probably to avoid other people to register the similar domain as you..
So that, register it by your own to avoid any confusing..

As far as I know search engines do not like multiple domains pointing to the same website, as they think this is black hat search engine optimization. They are right at a point because a keyword rich domain effectively changes search engine rankings.

We use multiple domains for our site. We also use multiple domains to point to INTERNAL pages in our site:

It's much easier to remember http://www.handsondomains.com and have it point to internal pages rather than having a long URL to remember. The same goes for specific hosting packages, dedicated servers, webdesign or ssl certificates.

Running multiple domains to a website is common practice, and when done correctly, google and other search engines appreciate it. In the 10+ years of operating our business in this manner, we have not been penalized by any of the search engines for this practice.

Yes, I think the same!

Multiple domains, used correctly, do not have a problem. When you try to TRICK a search engine, that's when things go sour.

Multiple domains pointing to the same location is also not normally a problem, but don't expect the multiple domains to be indexed, only the original domain would be listed.

Also, make life easier for search engines. Setup a robots.txt and specifically tell them NOT to index those parked domains. Setup sitemaps etc and excluse the domain.

If your purpose to register multiple domains is to somehow trick the search engines to believe that you have a ton of content, those days are LONG gone. Save your money and time, and invest in legitimate traffic.

well I bought .com .net .org .us .info so other companies couldn't buy those domains and then direct it to there own domain. I did it to prevent corporate espionage.

Anyway, it is impossible to protect the brand fully if you select this strategy!

So would an example like this be something like Google how there's countless Google sites? I know there's quite a few others as well, but I can't think of them at the moment.

I know there's even some that do it so in case you miss-spell the url then you're not taken to some random site, but rather the site itself. Like many sites have a .ca and .com.

Mircosoft does this, yahoo does this, google (as mentioned) does this, and hey why not - WE do it

Wrong spelling was a big deal a few years ago, and even today we have a few domains that are spelled wrong specifically to catch the traffic we would have missed.

But for us, primarily we use additional domains to link to internal folders/files directly. We also use certain domains in marketing (offline marketing) as it's easier to print "handsonhosting" than it is "handsonwebhosting" and hope the user doesn't spell it wrong.

I think its the appearance of domain name sharks that has prompted people to purchase a few domain names for a site. I have in the past purchased the .com .co.uk & .net for one site.
I think more recently the need for this isnt as high as google search engine has improved over the years & if somone really wants to find your site they will.
On the other hand, having someone gazzump you & purchase a domain name you have established as a brand name that was up for renewal is a bummer, so it helps to have a couple of other linked domains incase this happens.

I agree with you.
I would like to try this method too, but I just don't see it's benefits. Anyone can give a better explanation?

I think it's a good idea as long as you are dedicated to the site/domain/company name and plan to be around for a long time and run a real business. I've seen people register all 3 (.com/.net/.org) and never get the site off the ground only to let them all expire or only retain the .com in the end.

If you mean different domain names pointing to the same site that is okay too as long as it isn't spamming (like another user said different domain names for company services or internal pages) seems like a good strategy.

I have 2 domains that are basically the same site but one is in Portuguese and the other in English. Both point to the same location now and I did this due to the spelling of one of the words for the chosen language.

I think you just should just register different gTLDs and your country tld for the same website...I feel otherwise, you'd end up spending too much money..