These are the computers that started the Apple II line; the Apple II debuted in April 1977, and the II+ in 1979. They were sold with 1 MHz 6502 processors, a NTSC or PAL video out connector with ability to do 40x24 text (uppercase letters and punctuation only), High (roughly 280x192, 4 (only early IIs) or 6 fixed colors) and Low (40x48, 16 fixed colors) resolution color graphics, sound, plus they have 8 expansion slots to add peripherals. (Slot 0 was essentially reserved for RAM/ROM upgrades, though.)

The II and II+ were sold with anywhere from 4-48K of RAM. The first versions had Steve Wozniak's Integer Basic built into ROM, while later versions had the more powerful Applesoft Basic. Although a cassette tape interface was provided, most systems used the external 140K per side (manually flipping the disk to access the other side was extremely common) 5.25" Disk II drive.

Common upgrades included adding joysticks or paddles, 80-column video cards (not the same as a IIe 80-column card), more memory or faster processors (Transwarp, Zipchip, Rocketchip).

The 'europlus' variant is a II+ with a different logo on the front case, and the ability to put out the video in black and white PAL format. Thus, they're not easily usable in the US, Japan, Korea, and other countries using NTSC video.

With 48 to 64K of RAM, a II or II+ can run most of the Apple II game classics, as well as thousands of pieces of software. Early versions of Appleworks (integrated Word Processor, Database, Spreadsheet) could be run on a II or II+ with 128K and a program called PlusWorks.

Recommended configuration: 16K language card (in slot 0 with a ribbon cable running to the RAM) which extends the system to 64K RAM, an 80-column video card, shift key modification (allows the shift keys to be used), and modified character ROMs to do lower case.

Early external hard drives, such as the Sider or Corvus can also be added. You can add memory in various ways, but 95% of Apple II programs that require 128K probably will not work in a II or II+, no matter how much RAM you have-- they tend to require a IIe or better.

Information Courtesy of the Apple FAQ, Part II