Yes, that’t true. If you have an email account with gmail, you have multiple email ids with single inbox.
gmail ignores any period(“.”) within the username.
What this means?
If your gmail user id is “abcd”, the user ids like “a.bcd, ab.cd, a.b.c.d” etc are all yours. That means, firstname.lastname@example.org, email@example.com etc are all yours. You can even use any of these ids to login to your account.
I see two ways in which we can properly use this feature.
1. We may want to signup for multiple accounts with some service providers who need a seperate email id for each account. Usine this feature, we can do that and since all the accounts share the same inbox, tracking will be easier.
2. We can give a seperate id(a.bcd, abcd) to different groups(friends, business etc) and apply some filters to our account to easily classify them.