The two types of disk can be distinguished at a glance by the number of holes on the bottom edge of the disk. DD disks have one hole that can be covered by an integral plastic tab. HD disks have two holes, of which, one has no tab. HD disks are usually labelled as such on the disk. The plastic tab is a safety feature which is used to write disable or write enable the disk.
All microcomputers have a slot for a floppy disk.
If you move work between computers there is a risk of a computer virus being transferred. A virus attaches itself to a file for permanent storage but will copy itself into the computers memory where it will also corrupt other peoples work. It is your responsibility to ensure that you only work in a non-infected environment. There are applications on the network to check disks for viruses, you are strongly advised to use them on any floppy disk you intend to use with the system. Note HT.MC.04 .