Events and tasks are the engine of sales productivity. With Salesforce, you can be prepared for any meeting and know which task is your highest priority at any time. Track meetings and tasks together in lists and reports to keep track of all your leads, contacts, opportunities, accounts, and campaigns. Activity Management allows you to see your own activity as well as the activities of the people who are below you in the role hierarchy in Salesforce. Some permissions come into play. If activity sharing model is "Controlled By Parent",people with "View All" permission for the type of object on the related record can view the activity. If you are assigned to the activity and if you have the "Edit Tasks" and "Edit Events" permissions then you can delete the activity. Salesforce displays the reminders of event and task in a reminder window. When you log in to Salesforce Classic, a sound plays if you have reminders that have been triggered since the last time you logged in. One can perform customizations like customizing reminders in the personal settings.