Legacy Glossary

This is a glossary of older terms. While many of the definitions are unchanged, some of the definitions may be out of date and some of the terms may no longer be in use in the Data Center industry. This legacy glossary provides definitions for hundreds of information and communications technology (ICT) and data center terms and acronyms. Arranged alphabetically and searchable, the glossary explains common industry vocabulary.
1 A B C D E F G H I K L M N O P R S T U V W Z

A high-performance computer made for high-volume, processor-intensive computing. This term is used for the processor unit, including main storage, execution circuitry, and peripheral units, usually in a computer center, with extensive capabilities and resources to which other computers may be connected so they can share facilities

Management Information Base (MIB)

A repository of information to describe the operation of a specific network device


Heat release rate in units of 1000 British thermal units (BTU) per hour

Mean Time to Repair (or Recover) (MTTR)

The expected time to recover a system from a failure, usually measured in hours

Measured Power

The heat release in watts

Media Access Control (MAC)

The data link sub-layer that is responsible for transferring data to and from the physical layer


Internal storage areas in the computer. The term memory identifies data storage that comes in the form of silicon, and the word storage is used for memory that exists on tapes or disks. The term memory is usually used as a shorthand for physical memory, which refers to the actual chips capable of holding data. Some computers also use virtual memory, which expands physical memory onto a hard disk


The final results of a benchmark. The significant statistics reported from a benchmark run. Each benchmark defines what are valid metrics for that particular benchmark


A chip that contains a CPU. The terms microprocessor and CPU are quite often used interchangeably


Provides a fault-tolerant connection from the blade server to the server chassis and other components. The midplane replaces an average of nine cables typically required in rack and pedestal server configurations, eliminating excessive cables

Minimum Efficiency Reporting Value (MERV)

Previously there were several specifications used to determine filter efficiency and characteristics. ASHRAE has developed the MERV categories so that a single number can be used to select and specify filters


Multimode fiber


The main circuit board of a computer. The motherboard contains the CPU, BIOS, memory, input/output ports, expansion slots, connectors for attaching additional boards and peripherals, and the controllers required to control those devices


Mean time between failure