Yes, and be aware that @Delta is more of a Delta news/PR/announcement account while @DeltaAssist is the account for actual help.
DP's explanation is good. Just make sure you understand what a tweet is and what a direct message is. Tweets are public (unless you set a private account) while direct messages are like short e-mails that are private between you and the recipient. I only DM with @DeltaAssist now that they follow me, usually with "Name, Skymiles # OR Conf #, and description of problem"