In many examples on this wiki people use “non-literal” paths. This means that the path you type isn't the same as what is in the example.
dd if=/dev/sda of=/PATH/TO/BACKUP
This is an example of a non-literal path. The author doesn't want you to literally type ”/PATH/TO/BACKUP” but rather something more like this.
dd if=/dev/sda of=/media/MMC-SD/partition1/backup.img
This would address a file named “backup.img” on your SD card. That is presuming the sd card had no name.
The reason why people use non-literal paths in the wiki is because there is no way to tell what the real path will be. If your sd card happened to be from your camera and it was named “photos” then writing the same file above would be addressed ”/media/MMC-SD/photos/backup.img” also the “MMC-SD” will change depending on what you have plugged in. any flash drive, external hard drive, or usb dvdrom drive will likely use a different name.
The only parts you can be sure of is that they will be mounted in ”/media” also a link is normally added into your home directory. Example you insert a sd card and suddenly in your home directory appears a directory called “MMC-SD” this is not a real directory but a “symbolic link” to the directory in ”/media”