Deactivating Vs Deleting Facebook Account?

What is the Difference in Deactivating and Deletion of Facebook Account?

If you deactivate your account:

• Your timeline disappears from the Facebook service immediately.
• People on Facebook will not be able to search for you. Some information, like messages you sent, may still be visible to others.
• We save your timeline information (friends, photos, interests, etc.), just in case you want to come back to Facebook at some point. If you choose to reactivate your account, the information on your timeline will be there when you come back.

A lot of people deactivate their accounts for temporary reasons and expect their timelines to be there when they return to the service. This option gives you the flexibility to leave and come back whenever you want.

If you permanently delete your account:

• You will not be able to regain access to your account again.
• Most personally identifiable information associated with it is removed from our database. This includes information like your email address, mailing address, and IM screen name. Some personally identifiable information may remain, such as your name if you sent a message to someone else.
• Copies of some material (photos, notes, etc.) may remain in our servers for technical reasons, but this material is disassociated from any personal identifiers and completely inaccessible to other people using Facebook. 

Source: Facebook.com