Users can Delete their dashboards if they no longer require them or can Copy-Paste their Dashboards to create a true copy of their existing dashboards as per their requirement.
To delete you dashboard select the dashboard and click on Delete.
A confirmation pop-up will appear. In the confirmation pop-up click on Yes. Your dashboard will get deleted.
To copy your Dashboard, select the dashboard and click on Copy.
The Paste icon will get enabled. Click on Paste.
A copy of your selected dashboard will get created.