RAM - (random access memory) is the place in a computer where the operating system, application programs, and data in current use are kept so that they can be quickly reached by the computer's processor.

SIMM - A SIMM is a module containing one or several random access memory (RAM) chips on a small circuit board with pins that connect to the computer motherboard. Since the more RAM your computer has, the less frequently it will need to access your secondary storage (for example, hard disk or CD-ROM), PC owners sometimes expand RAM by installing additional SIMMs. SIMMs typically come with a 32 data bit (36 bits counting parity bits) path to the computer that requires a 72-pin connector. SIMMs usually come in memory chip multiples of four megabytes.

DIMM - A DIMM (dual in-line memory module) is a double SIMM (single in-line memory module). Like a SIMM, it's a module containing one or several random access memory (RAM) chips on a small circuit board with pins that connect it to the computer motherboard. A SIMM typically has a 32 data bit (36 bits counting parity bits) path to the computer that requires a 72-pin connector. For synchronous dynamic RAM (SDRAM) chips, which have a 64 data bit connection to the computer, SIMMs must be installed in in-line pairs (since each supports a 32 bit path). A single DIMM can be used instead. A DIMM has a 168-pin connector and supports 64-bit data transfer. It is considered likely that future computers will standardize on the DIMM.

DRAM - Dynamic random access memory (DRAM) is the most common kind of random
access memory (RAM) for personal computers and workstations.

SRAM - (static RAM) is random access memory (RAM) that retains data bits in its
memory as long as power is being supplied.

SDRAM - Synchronous DRAM (SDRAM) is a generic name for various kinds of DRAM that are synchronized with the clock speed that the microprocessor is optimized for.

Parity - In computers, parity (from the Latin paritas: equal or equivalent) refers to a technique of checking whether data has been lost or written over when it's moved from one place in storage to another or when transmitted between computers.

Nanoseconds - The measure of the speed of a chip: a billionth of a second. The lower the number the faster the chip. For example, 60ns is faster than 70ns.

Low Profile- Low profile is related to the height of the memory modules. Some computers can use standard profile or low profile, some require low profile. Some like the iMac G3 233/266/333; PowerBook Wallstreet & Lombard, have one standard slot and one low profile slot. The PowerBook G3 FireWire takes 2 standard size modules. The PowerBook G4 takes two low profile modules. The iBooks allow for only 1 low profile module.

Pismo- The PowerBook G3 FireWire was the last G3 PowerBook and was replaced with the PowerBook G4 'Titanium'. It was also known as the 'Pismo' and was released in the year 2000. This was the first Powerbook with built in FireWire ports.

Sawtooth- Sawtooth was the nickname of the first PowerMac G4 models with the AGP slot motherboard. The very first G4 was just a Blue and White G3 logic board with a G4 processor ZIF. That first G4 model had only PCI slots (same as the Blue and White G3) and was nicknamed the G4 'Yikes' model.

PCMCIA- PCMCIA slots are found on laptop computers. These slots accept credit card like expansion cards that slide in to add FireWire, Wireless, USB, and other features, even additional storage cards.

AGP- AGP is a processor direct video card slot that allows for higher performance video card solutions. As opposed to a standard PCI slots, the AGP slot is only for video and optimized for that purpose.

ATA and IDE are hard drive interface standards. IDE and ATA are
interchangeable in terms of hard drives and the interface they support. Simply put IDE/ATA is a competing interface standard to SCSI. When you see ATA/33 or ATA/100, the number after the '/' is the maximum megabytes per second that is supported for that device or bus.