Why are Accounts and Contacts connected?

Why are Accounts and Contacts connected?

I'm just getting started on creating a database of clients for our company in Zoho CRM. I've imported a big list of contacts through our newspaper into the 'Contacts' tab. They also were all imported to the 'Accounts' section at the same time for some reason, and when I delete an 'Account' name it also deletes it in 'Contacts'. I do not want this. I want to have separate entries in these two sections that remain independent of each other. Must be some simple checkbox I'm missing??

Thanks in advance for any help!
Jesse