Check this link 4 an explanation on the models....
http://civic.vtec.net/civic-88/specifications.html
Here's a sample...
Standard Equipment
STD: 1.5L TBI 16 valve 70hp, 4spd manual, door mounted seat belts, 50/50 split rear seats, remote fuel and hatch release, rear defogger, 165/70R13 tires
DX adds: 1.5L TBI 16 valve 92hp, 5spd manual or 4spd auto, power steering w/auto tranny, motorized front belts (4dr), rear wiper/washer (3dr), tilt wheel, cargo cover (3dr), interval wipers, 175/70R14 tires