Think of an alias like an alternative path to the same destination. It can apply to domain names, subdomains, and email addresses.
For example, Blogger and Tumblr allow for custom URLs for FREE. If you own your own domain name, you can turn your blog into [domain].com or blog.[domain].com.
Or you can get a short URL! Like dvdv.kim. If paired with the bit.ly service, you can share and track your own branded URLs and track clicks. With bit.ly you can have the root domain forward to your website or blog.
Email address aliases are cool, too.
If you use a domain name, some domain registrars permit domain address forwarding. So you can setup name@[your domain name] to forward emails to your personal inbox.
If you have an Outlook account, you can go to Settings > Add an alias. If the end of your address is @hotmail.com or @live.com, you can get an @outlook.com address that goes to the same mailbox.
After you do that, you can use inbox rules to filter messages sent to certain addresses.
For example, make an inbox rule that "when To: field = [alias address], put in [alias] folder."
This means you can virtually manage several separate inboxes in one mail account organized by folders.
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