What is the difference between using "FORMAT" and "DELETE"

What is the difference between using "FORMAT" and "DELETE"

There are two methods to erase the images that are stored in your memory card.

Using the camera's menu to "format" removes all files and sets up the memory card for use in the camera. "Delete" on the other hand removes one image after another. Therefore, it is a good idea to occasionally format a memory card (in the camera and not on a computer) but delete the images if you wish to cleanup the memory card daily.

All Nikon cameras have a memory card format option, either in the Set Up Menu or in some models on the camera body.
As explained above, the reason why a memory card needs to be formatted is simple, the card when formatted performs at it's optimum. Formatting after each download is one way of making sure that you will have less chance of ending up with card corruptions. Also being at it's optimum, the memory card can read and write at it's best for the camera you are using.

Nowadays, many users may be using card readers to copy the images from the memory card to their computer. Operating systems such as Windows XP, Windows 2000 and Mac OSX tend to place tags onto the card as part of their process, and in time if the memory card is not looked after they may even become corrupted. A corrupted memory card means that your data is damaged and can cause the memory card to not perform as expected. In many cases not readable in either the camera or the card reader. If your card has reached this level and you cannot format the memory card in the camera, it is suggested that you contact the card manufacturer to see if there is any Data Recovery Software available to recover your lost images.