The Apple IIc is the fourth model in the Apple II series of computers. It is Apple's first attempt to design a portable computer. At 7.5lbs, today it would be considered luggable rather than portable. The "c" in the name stood for compact. The case was smaller, and had venting slots on top, so it could no longer support a monitor. Apple provdied a separate stand for that.
The IIc used a new CMOS-based 65C02 CPU that had 27 more instructions over the 6502. Unfortunately some software used undocumented instructions on the 6502, that were not carried over in the design for the 65C02, resulting in incompatibilities.
The text display of the IIc added 32 unique characters that could be combined to create simple icons, windows and menus so a simple Graphical User Environment could be simulated out of text characters.