APS - artificial pancreas system. Sometimes also referred to as “AP”

CGM - continuous glucose monitor, a temporary glucose sensor that is injected into your skin (the needle is removed) for 3-7 days and, with twice a day calibrations, provides BG readings approximately every 5 minutes.

#OpenAPS - stands for Open A(rtificial) P(ancreas) S(ystem). It is an open-source movement to develop an artificial pancreas using commercial medical devices, a few pieces of inexpensive hardware, and freely-available software. A full description of the #OpenAPS project can be found at #OpenAPS (with the hashtag) generally refers to the broad project and open source movement.

OpenAPS - refers to an example build of the system when used without a hashtag (#)

openaps - the core suite of software tools under development by this community for use in an OpenAPS implementation

Bolus - extra insulin given by a pump, usually to correct for a high BG or for carbohydrates

Basal - baseline insulin level that is pre-programmed into your pump and mimics the insulin your pancreas would give throughout the day and night

IOB - Insulin On Board, or insulin active in your body. Note that most commercially available pumps calculate IOB based on bolus activity only. An OpenAPS implementation calculates and refers most often to net IOB, which takes into account any adjusted (higher or lower) basal rates as well as bolus activity.

DIA - duration of insulin action, or how long the insulin is active in your body. (Ranges 3-6 hours typically)

CR - carb ratio, or carbohydrate ratio - the amount of carbohydrates for one unit of insulin. Example: 1 u of insulin for 10 carbs

ISF - insulin sensitivity factor - the amount of insulin that drops your BG by a certain amount mg/dl. Example: 1 u of insulin for 40 mg/dl

NS, or Nightscout - a cloud-based visualization and remote-monitoring tool.