Administrators have the ability to create fields that are un-editable by basic users. Basic users are still able to see and access the fields but are not able to change the data to add an extra level of security when needed. 

When creating or editing a Custom Field, the admin will have the option to lock the field using the Edit toggle.

Any admin or executive on the account will still be able to edit that field but non-admin team leaders and team members will not be able to. For basic users, the field will show the value but it will be grayed out on the record. Even if the basic user is the owner of the record, they will not be able to edit the locked field.

On the list view pages, the information will be visible as normal, but the cell will not be editable by basic users. If they click, nothing will happen.