There's no explicit "ban" permission, with the exception of Flag As Spammer, which you can enable/disable when configuring Moderators via the Members -> Moderators page in the ACP.
As for standard bans, those are issued via the ACP or with the use of Warnings. Members -> Content Moderator -> Warnings. Choose a number of warning points that members on your site can accrue that would lead to a ban, then create a warning reason that assigns those points, essentially creating a ban tool. For example, with WebFlake, when a user reaches ten (10) warning points, they are automatically banned but we also have an "extreme violation" reason that issues ten points, giving our Moderators the ability to ban.
Flag As Spammer is the only one-click ban option on the front-end.