Thank you esmi, for your valuable input. You have set my mind at rest.
Thanks esmi and Rod for your replies. Correct me if I am wrong, but from what I understand from you both is that it is the best idea to develop the site structure (theme, etc.) locally, and then add the content directly online. Therefore, as Rod states, there is a need for two different databases – one for the local development server and one for the web server. I assume that it is easy enough to upload everything except the local database when updates to the theme or structure are carried out?