It's a device which delivers insulin through a tube and cannula to under the skin. Basically, continually connected to body, although can be disconnected fro short periods eg for baths / showers / swimming / other activities not suitable for a family forum! Rates of insulin can be adjusted, both basal (underlying) and bolus (for meals / snacks).
Having said all that, it's also important to note that it's difficult enough for people with type 1 diabetes to get an insulin pump on NHS, and virtually unheard of for people with type 2, although some people self fund their own initial purchase and subsequent and continuing need for consumables eg cannulae, tubing sets etc.