Agreed principles of protocol. Standards are set by committees working under various trade and international organizations.

ECP

Extended Capabilities (Parallel) Port An upgrade to the original parallel port on a PC, which gives you: Transfer rates of more that two million bytes per second; bidirectional 8-bit operation (a standard parallel port has only 4 input bits); support for CD-ROM and scanner connections; 16-byte FIFO buffer; support for run length coding data compression.
Enhanced Integrated Drive Electronics An improved interface to the IDE hard disk interface. Enhanced IDE allows you to attach hard disks of larger than 528 megabytes (the largest normal IED will handle) up to a maximum of 8.4 gigabytes. Enhanced IDE has a data transfer rate of between 11 and 13 megabytes per second, compared to the 2 to 3 megabytes per second, which normal IDE drives sport.
In a computer a "bus" is an electrical channel for getting information and commands in and around the computer. It is the way the central microprocessor running the computer gets its information and commands to the various peripheral devices or device controllers, such as video cards, hard disk cards, etc.

EPP

Enhanced Parallel Port A new hardware and software innovation (and now a standard) which allows computers so equipped to send data out their parallel port at twice the speed of older parallel ports, i.e. those that came on the original IBM PC. The EPP conforms to the EPP standard developed by the IEEE 1284 standards committee. The EPP specification transforms a parallel port into an expansion bus that theoretically can handle up to 64 disk drives, tape drives, CD-ROM drives, and other mass-storage devices. EPPs are rapidly gaining acceptance as inexpensive means to connect portable drives to notebook computers.
Enhanced Small Device Interface An interface which improves the rate of data transfer for hard disk drives and increases the drive's storage capacity.
Institute of Electrical and Electronics Engineers, Inc. www.ieee.org IEEE founded in 1884, have the world's largest technical professional society, consisting of over 320,000 members in 147 countries. The IEEE's technical objectives "focus on advancing the theory and practice of electrical, electronics and computer engineering and computer science." It is a significant standards-making body responsible for many telecom and computing standards, including those standards used in LANs--e.g. the 802 series.

ISA

Industry Standard Architecture The most common bus architecture on the motherboard of MS-DOS computers. The ISA bus was originally pioneered by IBM on its PC, then its XT and then its AT. ISA is also called the classic bus. It comes in an 8-bit and 16-bit version. Most references to ISA mean the 16-bit version (which carries data at up to 5 megabytes per second).
Personal Computer Memory Card International Association Standardizes packages for memory and input/output (modems, LAN cards, etc.) for computers, laptops, palmtops, etc. For each there is a specific set.

SSA

Systems Applications Architecture A set of specifications written by IBM describing how users should interface with applications and communications programs. The idea is to give all software "a common feel" so that training will be less burdensome. Plus all software written to SAA specifications will provide similar screen layouts, menus and terminology.
TWAIN (technology without an important [interesting] name) It is a program that lets you scan an image (using a scanner) directly into the application (such as PhotoShop) where you want to work with the image. Without TWAIN, you would have to close an application that was open, open a special application to receive the image, and then move the image to the application where you wanted to work with it. The TWAIN driver runs between an application and the scanner hardware. TWAIN usually comes as part of the software package you get when you buy a scanner. It's also integrated into PhotoShop and similar image manipulation programs. The software was developed by a work group from major scanner manufacturers and scanning software developers and is now an industry standard. In several accounts, TWAIN was an acronym developed playfully from "technology without an important name." However, the Hewlett-Packard site says that it is not an acronym but stands for the bringing together of applications and scanners in a "meeting of the TWAIN" (meaning the bringing together of two sides). The separate TWAIN Web site says that it doesn't stand for anything. "TWAIN is TWAIN."