Since new computers come shipped with pre-installed drives, including MacBooks, they are usually already formatted and ready for immediate use, so, typically, the only times that you will need to format a drive is if you bought a new one (like an external drive or a USB drive, for example) and it has not been formatted yet or if it has already been formatted but the file system that it uses is not fully supported by your MacBook Pro. You format your MacBook Pro when you have a new drive and you want to prepare it for storing information, so what you do is erase its contents, tell your MacBook that you want to use that drive to store and process information, then to establish a file system that will determine how data will be organized afterwards. Formatting and reformatting your MacBook Pro both involves erasing whatever contents your drive (HDD, SSD, USB drives, etc ) may have had, but they do have a slight difference. After all, they sound pretty much the same, so they must probably do the same thing, right? “Formatting” and “reformatting” are two terms that are often used interchangeably in computer troubleshooting tutorials, so it can be pretty confusing for casual computer users who are not sure which of the two they need to do on their MacBook Pro or if there is actually any difference between the two at all.

If you have been having some issues with your MacBook Pro like noticeable slowdowns, applications frequently crashing, or programs refusing to work altogether, one of the solutions that you might be advised to do is to format or reformat your MacBook Pro.

How to reformat macbook pro harddrive