Introduced along with the Mac II in March 1987, the SE came with 1MB of RAM, one or two double-sided 800KB floppies, and space to mount an internal SCSI hard drive (second bay held either a hard drive or second floppy - no room for both). The SE was the first compact Mac with a built-in fan.
In 1989 Apple began to ship the SE with their high density floppy drive, known as the FDHD (floppy drive, high density) or SuperDrive (for its ability to read and write IBM-format floppies with additional software).
The SE was introduced as the low-end cousin of the hot new 16MHz Mac II. The SE was the first compact Mac with an expansion slot. One of the first add-in cards was an MS-DOS card.