I was playing around with the Events and Calendar functionality available in Salesforce and thought it would be worth sharing my understanding......... Here it is.......

Events:

Advantages

• You can add multiple Participants to an Event.
• The Participant could be a User, a Contact or a Lead.
• You can send Invites to all participants.
• You can associate any object with an Event.
• Meeting Invites display the start and end time according to the User's Time Zone.
• Out of the box 'outlook' / 'Lotus Notes' sync

Limitations:

• You cannot modify the meeting invite.
• You cannot add a custom LOOK UP field to your Event (Setup --> Activity Custom Fields).
• Meeting Invites display in the Time Zone of the Event creator for Participants who are Contacts (Obviously, they do not have a Time Zone).

• Only 1 x large text field
• Date cannot be used in formulas / workflows
• It is not simple to view all the events a participant has been to (attendees vs 'who' on the event)
• Invites have salesforce branding (can be removed with a black tab setting)
• Polymorphic fields (who and what) are difficult to use in formulas

Calendar:

Advantages:

• You have multiple views of your calendar (Weekly,daily,multi-user view etc).
• You can view event details straight from your calendar by just hovering over the date (Mini Page Layout's actually).

Limitations:

• You are allowed to create elapsing events. Salesforce does not stop you from creating an Event for a User even if he is BUSY.
• Calendar displays multiple Events side by side.
• The Calendar can only be placed in the Home Page.
• The Calendar is not customizable.