Understanding domain name extensions

A word to the wise here: Just because you registered your domain as a

.com doesn’t mean that someone else doesn’t, or can’t, own the very same
domain name with a .net. Therefore, if you register MyDogHasFleas.com,
and the site becomes hugely popular among readers with dogs that have
fleas, someone else can come along, register MyDogHasFleas.net, and run
a similar site to yours in the hope of riding the coattails of your Web site’s
popularity and readership.