Users Having limited access to my the bacend of my site

Hello,

For some reason my users have limited access to the backend of my site. They can actually click the top of the page and go into the dashboard in my backend. I want to know how to set it where they cant have this access or where they can have any access at all to my backend? I have my new member set to become subscibers when they make account, however, they still have this access to my my backend? It is just limited access but I rather them not know how my website works via wordpress.

Thanks