Difference between daily RSS subscription and a newsletter?

I plan to install a newsletter using MailChimp to send out a weekly newsletter to subscribers.

I also will be installing a RSS subscription for readers to get daily updates as and when the blog is updated.

I need to know how do I set up a form that asks readers if they would like both of these options or just one form of subscription?

Or is it ok to just send both to subscribers? If that’s the case how do I manage my email addresses as won’t they be split between two subscription forms?

Or have I just got this all wrong?! Im confused!!