What is a Subscriber (User Role)?
A subscriber has limited permissions on a website. These users can log in to the dashboard, update their profile, and comment on posts.
More About Subscribers
You can allow user registration on your WordPress by navigating to Settings > General and checking the box for Anyone can register in the Membership section. Doing this will open your WordPress for user registrations. You will also want to ensure that Subscriber is selected in the dropdown menu next to New User Default Role.
Once this is complete, you can add a registration form and login link to your page. To do this, navigate to Appearance > Widgets and add the Meta widget to your sidebar. Then, you can view your subscribers by clicking on Users > All Users.